A Novel Interdisciplinary Course: Musical Acoustics and Health Issues In response to a college call for new interdisciplinary coursework in the Natural and Health Sciences, an undergraduate level course was created with focus on the physics and biophysics of sound. The physics of sound production in musical instruments is used as a model for understanding vocal production and sound ... Article
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Article  |   December 15, 2016
A Novel Interdisciplinary Course: Musical Acoustics and Health Issues
Author Affiliations & Notes
  • Donald Finan
    University of Northern Colorado, Greeley, CO
  • Deanna Meinke
    University of Northern Colorado, Greeley, CO
  • Disclosures
    Disclosures ×
  • Financial: Donald Finan and Deanna Meinke have no relevant financial interests to disclose.
    Financial: Donald Finan and Deanna Meinke have no relevant financial interests to disclose.×
  • Nonfinancial: Donald Finan is the Coordinator for Special Interest Group 19, Speech Science. Deanna Meinke has no relevant nonfinancial interests to disclose.
    Nonfinancial: Donald Finan is the Coordinator for Special Interest Group 19, Speech Science. Deanna Meinke has no relevant nonfinancial interests to disclose.×
Article Information
Hearing & Speech Perception / Acoustics / Hearing Disorders / Part 1
Article   |   December 15, 2016
A Novel Interdisciplinary Course: Musical Acoustics and Health Issues
Perspectives of the ASHA Special Interest Groups, December 2016, Vol. 1, 15-25. doi:10.1044/persp1.SIG19.15
History: Received July 28, 2016 , Revised November 11, 2016 , Accepted November 21, 2016
Perspectives of the ASHA Special Interest Groups, December 2016, Vol. 1, 15-25. doi:10.1044/persp1.SIG19.15
History: Received July 28, 2016; Revised November 11, 2016; Accepted November 21, 2016

In response to a college call for new interdisciplinary coursework in the Natural and Health Sciences, an undergraduate level course was created with focus on the physics and biophysics of sound. The physics of sound production in musical instruments is used as a model for understanding vocal production and sound reception, with emphasis on relevant issues of vocal and hearing health promotion. This project-based course, titled “Musical Acoustics and Health Issues,” was designed in collaboration with faculty from Audiology, Speech Science, Public Health, Music, Physics, Music Technology, and Science Education. Student performance is assessed through a series of eight hands-on projects designed to maximize active learning strategies. Course projects center on the concept of “sound as energy” and include the construction of string-based (cigar box guitar) and tube-based (PVC pipe didgeridoo) instruments. Course design, project details, and course outcomes are presented.

If you've taken or taught a course in the speech and hearing sciences, it's likely that you've encountered a number of music analogies used to help teach fundamental principles such as frequency, intensity, and resonance, but you may be surprised to learn that the connection between our disciplines and music is even stronger than principles of acoustics. Many speech and hearing professionals recognize the need for collaboration with performing arts professionals across both health promotion and rehabilitative domains. Clinical interaction with performing artists makes up a substantial part of the caseload for many speech and hearing professionals, and some clinicians specialize in speech, voice, and hearing issues related to performing artists. Further, there is a growing need for performing arts students to learn about health promotion activities related to their unique vocal and instrumental performance activities as accreditation standards for Schools of Music have begun to mandate the inclusion of teaching content related to health and injury prevention. “For music majors and music faculty and staff, general topics include, but are not limited to, basic information regarding the maintenance of hearing, vocal, and musculoskeletal health and injury prevention,” (National Association of Schools of Music, 2015, Sec. II F).
The incidence of music-induced hearing loss among musicians is up to 52% in classical musicians and up to 30% in rock/pop musicians (Chasin, 1996). The prevalence of noise-induced hearing loss in university student musicians aged 18–25 years is 45% based upon pure-tone audiometric thresholds (Phillips, Henrich, & Mace, 2010). A recent AuD capstone project completed at the University of Northern Colorado revealed that most music faculty do not feel that they have sufficient training or knowledge regarding hearing loss prevention to teach the curriculum themselves (Wakkinen, 2010). Similar findings have been reported regarding knowledge of vocal health for singers and singing teachers (Braun-Janzen & Zeine, 2009). As may be the case for hazardous noise/music exposure, lack of knowledge has the potential to lead to physical injury (possibly even career-ending injuries) of students as well as the instructors themselves. Indeed, Sataloff et al. (2012)  found that laryngeal abnormalities were common in singing teachers.
In 2013, the College of Natural and Health Sciences at the University of Northern Colorado launched an initiative to develop novel coursework. Specifically, the call requested active learning pedagogical approaches to address multidisciplinary “problems.” To this end, we have developed an interdisciplinary (Speech Pathology, Audiology, and Music) undergraduate level course covering the physics and biophysics of sound production and reception with emphasis on music and speech, which incorporates issues related to auditory and vocal injury prevention. The course, titled “Musical Acoustics and Health Issues,” was designed in collaboration with numerous faculty from disciplines of Audiology, Speech Science, Public Health, Music, Physics, Music Technology, and Science Education. This single-semester course is team-taught, with faculty expertise in speech physiology, acoustics, music performance, audiology, auditory physiology, and hearing loss prevention. Course topics include sound production in musical instruments and in the human vocal tract, exploration of acoustic energy sources, energy transfer from various sound sources to the human auditory system, and the biophysics of sound reception in the auditory system (see Table 1). Issues related to health of the vocal mechanism and the auditory system are presented from both preventive and rehabilitative perspectives by incorporating health behavior science theory in teaching strategies.
Table 1. Student Learning Outcomes.
Student Learning Outcomes.×
Students will be able to: describe basic physical and biophysical principles of sound generation.
explain how modification of physical parameters will impact sound generation in the context of musical instrument and human voice production.
describe the relationship between applied energy and resultant sound intensity.
describe the biophysics of sound reception by the auditory system.
demonstrate how to measure various physical parameters of sound, with consideration of musical instrument and human voice production as well as auditory perception.
identify potential health risks of hazardous sound exposure to the auditory system and sound production of the vocal mechanism.
Table 1. Student Learning Outcomes.
Student Learning Outcomes.×
Students will be able to: describe basic physical and biophysical principles of sound generation.
explain how modification of physical parameters will impact sound generation in the context of musical instrument and human voice production.
describe the relationship between applied energy and resultant sound intensity.
describe the biophysics of sound reception by the auditory system.
demonstrate how to measure various physical parameters of sound, with consideration of musical instrument and human voice production as well as auditory perception.
identify potential health risks of hazardous sound exposure to the auditory system and sound production of the vocal mechanism.
×
Class Structure
The class was structured with active learning strategies following the principles of the 5e pedagogical model (Bybee et al., 2006) of “Engage, Explore, Explain, Elaborate, and Evaluate.” The course is entirely project-based, and students are required to complete a series of active learning projects under instructor guidance. In the spirit of the “flipped classroom” model, students are responsible for researching classroom activity topics prior to completing the hands-on experience. Whenever possible, real-world activities are utilized so as to maximize carry-over of course concepts (Banchi & Bell, 2008) and to provide opportunities for the development of self-efficacy related to positive health behaviors.
Of the goals of the 5e pedagogical model, perhaps it is the first, “engage,” that is the most difficult to achieve. During the planning stages of our course, we decided to focus on engagement by eschewing the traditional lecture (including the use of PowerPoint presentations) during classroom sessions. Instead, course sessions involve the presentation of a number of core topics and the judicious use of in-class demonstrations that spur questions and relevant but peripheral discussion. The remaining 5e goals (“explore, explain, elaborate, evaluate”) are easily addressed by the hands-on projects and associated homework assignments.
Approximately one-third of course sessions are dedicated to a series of eight hands-on learning activities. These projects center around the theme of sound as energy, with students exploring associated topics of sound production, transmission, recording, perception, and issues related to potential health risks to the auditory and phonatory systems (Table 2).
Table 2. Course Projects.
Course Projects.×
Projects Tasks Core Concepts
Project 1: Physics of Musical instruments Build a stringed instrument (cigar box guitar) and a tube instrument (PVC pipe didgeridoo). Basic acoustics and musical acoustics, sound as vibration, physics of sound production and resonance, sound source as energy source.
Project 2: Electronic Sound Transducer Function & Use Interpretation of specification values for sound reinforcement equipment (microphones, loudspeakers, amplifiers). Sound as energy, transfer functions, analog to digital conversion, digital file compression.
Project 3: Digital Music Player Function & Use Exploration of functional parameters and potential hearing health risks with various headphones and earphones as connected to personal digital music players. Analog to digital conversion, digital recording and data compression, introduction to hearing health risk.
Project 4: Sound Level Measurement Investigation of functional parameters of sound measurement devices (standalone sound level meters & smartphone-based sound level meter apps). Sound as energy, sound pressure and sound power, inverse square law applied to sound propagation, sound level measurement.
Project 5: Acoustic Environments & Sound Exposure Measure sound pressure levels of a live amplified band in a controlled environment (recording studio). Sound as energy, effects of acoustic environments on sound level measurement and exposure.
Project 6: Hearing Health Risks & Injury Prevention Assess personal hearing status and interpret results with focus toward monitoring hearing status, selection, and measurement of hearing protector devices based on performance characteristics. Sound as energy that can potentially be damaging, hearing and hearing protector fit assessment and interpretation, hearing health risk and preventive strategies
Project 7: Voice Health Risks & Injury Prevention Investigation and assessment of vocal production characteristics. Identify risk factors for vocal damage. Sound as energy relative to the vocal folds as source of vibration, vocal health risk and injury prevention.
Project 8: Final Presentation Expansion on a previous project culminating in in-class presentation. Any core concepts may be revisited.
Table 2. Course Projects.
Course Projects.×
Projects Tasks Core Concepts
Project 1: Physics of Musical instruments Build a stringed instrument (cigar box guitar) and a tube instrument (PVC pipe didgeridoo). Basic acoustics and musical acoustics, sound as vibration, physics of sound production and resonance, sound source as energy source.
Project 2: Electronic Sound Transducer Function & Use Interpretation of specification values for sound reinforcement equipment (microphones, loudspeakers, amplifiers). Sound as energy, transfer functions, analog to digital conversion, digital file compression.
Project 3: Digital Music Player Function & Use Exploration of functional parameters and potential hearing health risks with various headphones and earphones as connected to personal digital music players. Analog to digital conversion, digital recording and data compression, introduction to hearing health risk.
Project 4: Sound Level Measurement Investigation of functional parameters of sound measurement devices (standalone sound level meters & smartphone-based sound level meter apps). Sound as energy, sound pressure and sound power, inverse square law applied to sound propagation, sound level measurement.
Project 5: Acoustic Environments & Sound Exposure Measure sound pressure levels of a live amplified band in a controlled environment (recording studio). Sound as energy, effects of acoustic environments on sound level measurement and exposure.
Project 6: Hearing Health Risks & Injury Prevention Assess personal hearing status and interpret results with focus toward monitoring hearing status, selection, and measurement of hearing protector devices based on performance characteristics. Sound as energy that can potentially be damaging, hearing and hearing protector fit assessment and interpretation, hearing health risk and preventive strategies
Project 7: Voice Health Risks & Injury Prevention Investigation and assessment of vocal production characteristics. Identify risk factors for vocal damage. Sound as energy relative to the vocal folds as source of vibration, vocal health risk and injury prevention.
Project 8: Final Presentation Expansion on a previous project culminating in in-class presentation. Any core concepts may be revisited.
×
The course is limited to 30 students per section due to the intensive oversight and space limitations required by the in-class projects. The first two projects require table space and tools for building, and most of the remaining projects require students to explore in-class demonstrations at a single central location. The course does require substantial resources for in-class demonstrations as well as for the individual projects, and course fees are assessed to pay for many of these materials (see Appendix A). Some of these resources are “consumables” for the construction of cigar box guitars and PVC pipe didgeridoos that the students keep. The course is open to students from any major, however, in addition to students in Audiology and Speech-Language Sciences (ASLS), students in Music and in the Performing Arts have been encouraged specifically to enroll. The class projects are designed to encourage interdisciplinary collaboration and are described below.
Projects
The first project, “Physics of Musical Instruments,” is covered over the first 5 weeks of the 16-week course. For this project, students explore concepts related to the physics of sound production in stringed instruments and tube-based instruments by building their own cigar box guitar and PVC pipe didgeridoo, respectively. For the cigar box guitars, students may choose to build a short (mandolin or ukulele type of instrument that we call a “mandolele”), medium (standard acoustic guitar string length), or long-scale (bass guitar) instrument (Figure 1). Each instrument has two strings and is tuned to the musical open tuning “G, D” (the first two notes of a G-Major chord). Students may choose to construct an instrument with more than two strings, however it is inadvisable to use more than three strings given the associated increase in required materials and complexity of construction. If three strings are used, they should be tuned to “G, D, G.” The guitars (including the mandolele and bass models) are constructed from a wooden cigar box (or equivalent), a neck of an appropriate length of 1″ × 2″ poplar wood (or equivalent) screwed on top of or underneath the lid of the box, and associated guitar hardware including tuning machines. Unlike on a conventional guitar, the guitar necks do not have frets (the metal strips used to select individual notes on the strings); instead, the students play the guitars by using a “slide” to press gently onto the strings at the neck in order to change pitch. In place of actual frets, students place fret markings on the side of the neck to indicate a diatonic (major) scale and/or a blues pentatonic (minor) scale (Figure 2). With this type of marking, students are able to play notes that are “musical,” even with no music experience or training. As such, we've termed this novel fretboard marking system “QuickPlay.” Students utilize formulas for string resonance and for calculations of fret positions during construction. The formula for string resonance is used during Project 1 and in Project 7 during explanation of phonatory system function. These and other core concepts are revisited and elaborated upon for the remaining projects.
Figure 1.

Cigar Box “Mandolele” (Left) and Guitar From Project 1. On the guitar (right), a pencil is used to support the strings as end of the neck and a large bolt is used as the guitar's bridge on the lid of the box. The mandolele utilizes small pieces of wood for the same purpose. Note that these are the authors' personal instruments and have been constructed with three strings each.

 Cigar Box “Mandolele” (Left) and Guitar From Project 1. On the guitar (right), a pencil is used to support the strings as end of the neck and a large bolt is used as the guitar's bridge on the lid of the box. The mandolele utilizes small pieces of wood for the same purpose. Note that these are the authors' personal instruments and have been constructed with three strings each.
Figure 1.

Cigar Box “Mandolele” (Left) and Guitar From Project 1. On the guitar (right), a pencil is used to support the strings as end of the neck and a large bolt is used as the guitar's bridge on the lid of the box. The mandolele utilizes small pieces of wood for the same purpose. Note that these are the authors' personal instruments and have been constructed with three strings each.

×
Figure 2.

Lateral View of a Cigar Box Guitar Showing our Novel QuickPlay Neck Marking Scale. The diatonic major scale is shown by the long lines and the pentatonic minor (blues) scale follows the crossed markings. The three additional short straight line markings indicate the location of the frets that would appear on a conventional guitar. The marking in the center of the neck (furthest to the right) indicates the octave note, located at half the length of the strings. This particular instrument also illustrates the “neck on top” construction, where the neck board is screwed to the top (lid) of the box from underneath. For this type of design, no cutting of the box is necessary, however an elevated bridge is required. Here, a metal cabinet handle forms the elevated bridge.

 Lateral View of a Cigar Box Guitar Showing our Novel QuickPlay Neck Marking Scale. The diatonic major scale is shown by the long lines and the pentatonic minor (blues) scale follows the crossed markings. The three additional short straight line markings indicate the location of the frets that would appear on a conventional guitar. The marking in the center of the neck (furthest to the right) indicates the octave note, located at half the length of the strings. This particular instrument also illustrates the “neck on top” construction, where the neck board is screwed to the top (lid) of the box from underneath. For this type of design, no cutting of the box is necessary, however an elevated bridge is required. Here, a metal cabinet handle forms the elevated bridge.
Figure 2.

Lateral View of a Cigar Box Guitar Showing our Novel QuickPlay Neck Marking Scale. The diatonic major scale is shown by the long lines and the pentatonic minor (blues) scale follows the crossed markings. The three additional short straight line markings indicate the location of the frets that would appear on a conventional guitar. The marking in the center of the neck (furthest to the right) indicates the octave note, located at half the length of the strings. This particular instrument also illustrates the “neck on top” construction, where the neck board is screwed to the top (lid) of the box from underneath. For this type of design, no cutting of the box is necessary, however an elevated bridge is required. Here, a metal cabinet handle forms the elevated bridge.

×
The didgeridoos are constructed from 1.5″ PVC pipe with a threaded adapter (or equivalent) for the mouthpiece (Figure 3). Didgeridoos are simple linear tube instruments that consist of a “closed” end (at the lips) and an open (distal) end, and they are played by blowing air through the lips to produce lip vibration in a manner analogous to vocal fold vibration. In addition to exploring the common properties of sound generation for the didgeridoo and for phonation, students explore the concept of air column resonance. The formula for closed-open tube resonance is used in order to measure and cut the PVC pipe to the length that will resonate at a “G” note one octave below the guitar. Electronic clip-on guitar tuners (or appropriate acoustic analysis software) are used in order to verify the note produced by the didgeridoo.
Figure 3.

An Example of a PVC Didgeridoo Showing a Threaded Adapter “Mouthpiece” (Top) and a Coupler Near the Bottom Used To Join Two Shorter Tubes. This didgeridoo is tuned to a G1 musical note, with a frequency of 49 Hz and wavelength of 6.945 meters. As the didgeridoo is a quarter-wave resonator, the length of the tube is set at approximately 1.75 meters (6.945 meters/4), including the length of the mouthpiece. The first resonance of this didgeridoo is at 49 Hz, or one octave below the lowest note of G2 on the full-size cigar box guitar (two octaves below the lowest note on the mandolele and matching the lowest note on the bass guitar). However, a second resonance of 146.8 Hz (D3) can be produced as well, which is one octave below the note of the second string of the full-size cigar box guitar. The authors believe that the Australian sticker adds some semblance of authenticity (and attractiveness) to this otherwise bland looking instrument.

 An Example of a PVC Didgeridoo Showing a Threaded Adapter “Mouthpiece” (Top) and a Coupler Near the Bottom Used To Join Two Shorter Tubes. This didgeridoo is tuned to a G1 musical note, with a frequency of 49 Hz and wavelength of 6.945 meters. As the didgeridoo is a quarter-wave resonator, the length of the tube is set at approximately 1.75 meters (6.945 meters/4), including the length of the mouthpiece. The first resonance of this didgeridoo is at 49 Hz, or one octave below the lowest note of G2 on the full-size cigar box guitar (two octaves below the lowest note on the mandolele and matching the lowest note on the bass guitar). However, a second resonance of 146.8 Hz (D3) can be produced as well, which is one octave below the note of the second string of the full-size cigar box guitar. The authors believe that the Australian sticker adds some semblance of authenticity (and attractiveness) to this otherwise bland looking instrument.
Figure 3.

An Example of a PVC Didgeridoo Showing a Threaded Adapter “Mouthpiece” (Top) and a Coupler Near the Bottom Used To Join Two Shorter Tubes. This didgeridoo is tuned to a G1 musical note, with a frequency of 49 Hz and wavelength of 6.945 meters. As the didgeridoo is a quarter-wave resonator, the length of the tube is set at approximately 1.75 meters (6.945 meters/4), including the length of the mouthpiece. The first resonance of this didgeridoo is at 49 Hz, or one octave below the lowest note of G2 on the full-size cigar box guitar (two octaves below the lowest note on the mandolele and matching the lowest note on the bass guitar). However, a second resonance of 146.8 Hz (D3) can be produced as well, which is one octave below the note of the second string of the full-size cigar box guitar. The authors believe that the Australian sticker adds some semblance of authenticity (and attractiveness) to this otherwise bland looking instrument.

×
With these simplistic designs, the guitars and PVC didgeridoos are easily made (and played) by even those with minimal or no construction or music experience. Assessment of Project 1 includes an in-class performance of each instrument that requires the students to demonstrate how to play the instrument as well as to orally explain the physics behind its function. In addition, there is a homework assignment that focuses on the core concepts taught for this project. It is crucial that the instructor(s) have experience with constructing these instruments. We suggest spending substantial time before the course begins in becoming familiar with the construction and physics of such instruments. The central theme concept of “sound as energy” is introduced during Project 1, with emphasis placed on topics of the physics of vibration, resonance, energy transfer, filtering, and musical harmony. Further, the concept of phonatory system function is introduced during Project 1 by bridging examples of string vibration for the guitars and lip vibration for the didgeridoos.
Projects 2–5 reinforce the concept of “sound as energy,” with topics covering electronic sound transduction, digital music recording and playback, sound level measurement, and the effects of acoustic environments on sound propagation and level. These projects involve “real-world” tasks where students interview sound reinforcement professionals (Project 2), explore functional characteristics of their own portable digital music players (Project 3), learn to use sound level meters (Project 4), and take a series of sound level measurements of a live amplified band (Project 5). Project 5 is conducted in a recording studio on campus which facilitates a discussion and exploration of room acoustics.
Projects 6 and 7 focus on health issues related to sound. For Project 6, students assess their own hearing status with audiological testing and explore the real-world fitting and attenuation performance characteristics of a number of different hearing protectors. These efforts are coordinated with more advanced graduate audiology students who are learning these assessment and intervention techniques in their own coursework. For Project 7, students assess their own vocal quality status using Praat computerized acoustic analysis software (Boersma & Weenink, 2016). For both of these projects, core concepts include health risk and injury prevention.
Assessment for Projects 2–7 is via written homework assignments that cover the core concepts for each project. Assignments are posted on the course online virtual learning environment with automated release and close timelines. Students receive individualized co-instructor feedback for each assignment.
Project 8 is a final oral presentation to the class of a topic of the student's choosing. Students select one of the previous seven projects and must expand on the core concepts beyond what was covered in the class. This permits students to explore their own interests or experience in greater depth and also provides an opportunity for engaging their personal creativity/experiences and development of oral presentation skills. Specifically, Project 8 incorporates all five goals of the 5e pedagogical model (Engage, Explore, Explain, Elaborate, and Evaluate).
Course Benefits
Benefit to ASLS Students
  • Increased knowledge base of issues related to individuals who are in the performing arts, allowing students to tailor their preventative and rehabilitative approaches to unique needs of the performing community.

  • Knowledge of the nature of sound production and biomechanical requirements of musical instruments will allow for an understanding of potentially hazardous risk factors and how to minimize or prevent them.

  • Experiential communication with performing artists and musicians who often have the same knowledge base, but differ in terms of application and terminology.

  • Recognition of the benefits and challenges related to personal health behavior change.

Benefit to Performing and Visual Arts (PVA) Students
  • Maintaining accreditation standards for the School of Music.

  • Understanding the nature of sound production in musical instruments as well as the human vocal tract. All Music students receive instruction in numerous instruments and in singing. Knowledge of the physics and biophysics required of sound sources will aid in the process of discovery.

  • Exposure to strategies and resources for prevention and remediation of discipline-specific injuries.

  • Experiential communication with audiology and speech-language students who often have the same knowledge base, but differ in terms of application and vocabulary.

  • Recognition of the benefits and challenges related to personal health behavior change.

Outcomes
At the end of the inaugural course semester, the students completed a brief survey focused on why they enrolled in the course, their overall impression of the course, and suggestions for improvement. Twenty percent of the students stated that they played a musical instrument, and 40% described themselves as a vocalist or singer. Students enrolled in the course for many reasons, with a number of students stating that the combination of music, speech, audiology, and noise induced hearing loss as course topics was a factor in their decision to enroll.
Below are a few selected (and representative) quotes regarding students' general overall impression of the course.
  • “The hands on nature of the class is really helping me understand the concept of acoustics better than I ever have.”

  • “The first project was challenging, but through the challenges I was able to learn more than if it was just a straight lecture course. ”

  • “I really thought this class was amazing. I have learned a lot since this class started, stuff that I never even thought about when I'm listening to music. I really enjoyed the hands-on experience that I received while making my guitar. I really enjoyed how we were able to figure out the speed of sound by being in this room. Very fun and experimental class.”

  • “It was a fun way to learn all the concepts. It also helped to visualize how sound acoustics work since we actually created them.”

  • “I'm glad I waited to fill this feedback because the didgeridoo I thought was pointless. After getting more understanding about quarter wave resonators and how that relates to the human body, I feel both the guitar and the didgeridoo were important to help me understand resonance.”

The following are selected responses to the request to provide both positive and constructive feedback for Project 1.
  • “While I liked the hands on measuring, I felt like it was time-consuming…”

  • “The instructions for the homework was a little vague…”

  • “It would be helpful if we went over the topics more formally, it was very scattered and made it difficult to condense it for the worksheet.”

Particularly notable are a number of student suggestions that demonstrate the engagement that students had with the course and the projects.
  • “Recommend attaching neck to bottom of box not top so bridge can vibrate the top without interference.”

  • “I am very thankful that I feel free to ask questions (sometimes several times) to really understand concepts. I wish we would have spent more time really getting into the physics while we worked. Playing the digeridoo is really hard!”

In summary, student comments suggest a high level of student engagement in the course. In general, student feedback was overwhelmingly positive, with constructive feedback (“suggestions for improvement”) largely as to be expected for an inaugural course delivery.
Conclusion
The acoustic, physical, and physiologic principles that underlie speech production and sound perception provide a basis for understanding both normal and disordered function. University professors have long realized the challenge in teaching these bioacoustic principles, as it often seems that retention of this knowledge ends after the final exam. Worse yet, generalization of this knowledge to more advanced concepts taught in later courses is often less than desirable. The challenge certainly lies with both the student and the teacher, however, as many bioacoustic principles are quite abstract. Students in the speech and hearing sciences often have a strong interest in music, and analogies can be explored between the processes of musical instrument function and speech production and sound perception. Students in the musical arts often have a desire to protect their health and career opportunities, and a better understanding of sound reception and production risk factors will serve as a foundation for developing their personal health behaviors.
Our new course, “Musical Acoustics and Health Issues,” was designed to engage and challenge students in audiology in the speech and language sciences as well as students in the performing arts. Our long-term goal is outreach to students from other fields of study as well by having the course approved for a university-wide Liberal Arts Core designation.
Make no mistake, this course is a challenge to both the students and to the instructor(s). Obtaining approval of a hands-on project-based course may be difficult in some institutions, and the thought of teaching a course in a flexible context guided by the student's understanding, questions, and exploration (i.e., without any dependency on formal PowerPoint lectures) can be daunting. Further, the logistics of securing an appropriate classroom (with adequate table space for building, ease of cleanup, and even noise considerations) and the requisite tools and supplies is not trivial. However, we have found Musical Acoustics and Health Issues to be one of our most enjoyable courses to teach, as students are clearly engaged with and interested in the subject matter. The unique opportunities to have informal conversations and mentoring/advising conversations with individual students during the project activities are personally valued. The “challenge” of foregoing the standard lecture format, while initially daunting, provides a rich opportunity for both student and instructor growth.
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Sataloff, R. T., Hawkshaw, M. J., Johnson, J. L., Ruel, B., Wilhelm, A., & Lurie, D. (2012). Prevalence of abnormal laryngeal findings in healthy singing teachers. Journal of Voice, 26, 577–583. [Article] [PubMed]×
Wakkinen, A. (2010). Attitudes, knowledge, and readiness levels of a university music school faculty regarding hearing loss prevention. Unpublished Doctoral Capstone, University of Northern Colorado, Greeley, CO.
Wakkinen, A. (2010). Attitudes, knowledge, and readiness levels of a university music school faculty regarding hearing loss prevention. Unpublished Doctoral Capstone, University of Northern Colorado, Greeley, CO.×
Appendix A
Resources
Consumable Materials
  • Cigar Box Guitars: Cigar boxes or equivalent (wood boxes in various sizes, 2.5″ × 1″ × 8″ poplar boards (or equivalent) to cut for guitar necks, acoustic guitar strings (light gauge A and D strings for guitar; G and high E strings for mandolele), bass guitar strings (light gauge A and D strings), tuning machines (2 per instrument), screws to attach the neck to the box, copper or PVC tubing for slides, material for guitar nut and bridge (small scrap wood pieces, large bolts, drawer handles, etc.).

  • PVC Didgeridoos: 1.5″ PVC pipe in 10′ lengths, 1.5″ PVC end-to-end couplers (to extend too-short pipe lengths if necessary), 1.5″ PVC MPT x S Adapters (didgeridoo mouthpieces).

Project Equipment
Tools (drills and drill bits, screwdrivers, small hand saws such as coping saws or similar, measuring tapes and rulers, files and sandpaper), noise dosimetry measuring systems, sound level meters and octave band filters, vocal assessment hardware and software, musician's flat attenuating and conventional industrial earplugs and earmuffs, electronic ear protectors, 3M E-A-R fit™ hearing protector fit-test system, vocal dosimetry system.
Equipment for In-Class Demonstrations in Addition to the Above
Microphones and preamplifier, loudspeaker and amplifier, loudspeakers and microphones for disassembly and inspection, equipment for demonstrations of resonance (various short lengths of PVC pipe, rope or Slinky spring, etc.), hearing loss and tinnitus simulator, vocal fold anatomical models, tuning forks, etc.
For details on construction, sourcing materials or additional information regarding project details, contact the authors at University of Northern Colorado http://www.unco.edu/nhs/audiology-speech-language-sciences/
Figure 1.

Cigar Box “Mandolele” (Left) and Guitar From Project 1. On the guitar (right), a pencil is used to support the strings as end of the neck and a large bolt is used as the guitar's bridge on the lid of the box. The mandolele utilizes small pieces of wood for the same purpose. Note that these are the authors' personal instruments and have been constructed with three strings each.

 Cigar Box “Mandolele” (Left) and Guitar From Project 1. On the guitar (right), a pencil is used to support the strings as end of the neck and a large bolt is used as the guitar's bridge on the lid of the box. The mandolele utilizes small pieces of wood for the same purpose. Note that these are the authors' personal instruments and have been constructed with three strings each.
Figure 1.

Cigar Box “Mandolele” (Left) and Guitar From Project 1. On the guitar (right), a pencil is used to support the strings as end of the neck and a large bolt is used as the guitar's bridge on the lid of the box. The mandolele utilizes small pieces of wood for the same purpose. Note that these are the authors' personal instruments and have been constructed with three strings each.

×
Figure 2.

Lateral View of a Cigar Box Guitar Showing our Novel QuickPlay Neck Marking Scale. The diatonic major scale is shown by the long lines and the pentatonic minor (blues) scale follows the crossed markings. The three additional short straight line markings indicate the location of the frets that would appear on a conventional guitar. The marking in the center of the neck (furthest to the right) indicates the octave note, located at half the length of the strings. This particular instrument also illustrates the “neck on top” construction, where the neck board is screwed to the top (lid) of the box from underneath. For this type of design, no cutting of the box is necessary, however an elevated bridge is required. Here, a metal cabinet handle forms the elevated bridge.

 Lateral View of a Cigar Box Guitar Showing our Novel QuickPlay Neck Marking Scale. The diatonic major scale is shown by the long lines and the pentatonic minor (blues) scale follows the crossed markings. The three additional short straight line markings indicate the location of the frets that would appear on a conventional guitar. The marking in the center of the neck (furthest to the right) indicates the octave note, located at half the length of the strings. This particular instrument also illustrates the “neck on top” construction, where the neck board is screwed to the top (lid) of the box from underneath. For this type of design, no cutting of the box is necessary, however an elevated bridge is required. Here, a metal cabinet handle forms the elevated bridge.
Figure 2.

Lateral View of a Cigar Box Guitar Showing our Novel QuickPlay Neck Marking Scale. The diatonic major scale is shown by the long lines and the pentatonic minor (blues) scale follows the crossed markings. The three additional short straight line markings indicate the location of the frets that would appear on a conventional guitar. The marking in the center of the neck (furthest to the right) indicates the octave note, located at half the length of the strings. This particular instrument also illustrates the “neck on top” construction, where the neck board is screwed to the top (lid) of the box from underneath. For this type of design, no cutting of the box is necessary, however an elevated bridge is required. Here, a metal cabinet handle forms the elevated bridge.

×
Figure 3.

An Example of a PVC Didgeridoo Showing a Threaded Adapter “Mouthpiece” (Top) and a Coupler Near the Bottom Used To Join Two Shorter Tubes. This didgeridoo is tuned to a G1 musical note, with a frequency of 49 Hz and wavelength of 6.945 meters. As the didgeridoo is a quarter-wave resonator, the length of the tube is set at approximately 1.75 meters (6.945 meters/4), including the length of the mouthpiece. The first resonance of this didgeridoo is at 49 Hz, or one octave below the lowest note of G2 on the full-size cigar box guitar (two octaves below the lowest note on the mandolele and matching the lowest note on the bass guitar). However, a second resonance of 146.8 Hz (D3) can be produced as well, which is one octave below the note of the second string of the full-size cigar box guitar. The authors believe that the Australian sticker adds some semblance of authenticity (and attractiveness) to this otherwise bland looking instrument.

 An Example of a PVC Didgeridoo Showing a Threaded Adapter “Mouthpiece” (Top) and a Coupler Near the Bottom Used To Join Two Shorter Tubes. This didgeridoo is tuned to a G1 musical note, with a frequency of 49 Hz and wavelength of 6.945 meters. As the didgeridoo is a quarter-wave resonator, the length of the tube is set at approximately 1.75 meters (6.945 meters/4), including the length of the mouthpiece. The first resonance of this didgeridoo is at 49 Hz, or one octave below the lowest note of G2 on the full-size cigar box guitar (two octaves below the lowest note on the mandolele and matching the lowest note on the bass guitar). However, a second resonance of 146.8 Hz (D3) can be produced as well, which is one octave below the note of the second string of the full-size cigar box guitar. The authors believe that the Australian sticker adds some semblance of authenticity (and attractiveness) to this otherwise bland looking instrument.
Figure 3.

An Example of a PVC Didgeridoo Showing a Threaded Adapter “Mouthpiece” (Top) and a Coupler Near the Bottom Used To Join Two Shorter Tubes. This didgeridoo is tuned to a G1 musical note, with a frequency of 49 Hz and wavelength of 6.945 meters. As the didgeridoo is a quarter-wave resonator, the length of the tube is set at approximately 1.75 meters (6.945 meters/4), including the length of the mouthpiece. The first resonance of this didgeridoo is at 49 Hz, or one octave below the lowest note of G2 on the full-size cigar box guitar (two octaves below the lowest note on the mandolele and matching the lowest note on the bass guitar). However, a second resonance of 146.8 Hz (D3) can be produced as well, which is one octave below the note of the second string of the full-size cigar box guitar. The authors believe that the Australian sticker adds some semblance of authenticity (and attractiveness) to this otherwise bland looking instrument.

×
Table 1. Student Learning Outcomes.
Student Learning Outcomes.×
Students will be able to: describe basic physical and biophysical principles of sound generation.
explain how modification of physical parameters will impact sound generation in the context of musical instrument and human voice production.
describe the relationship between applied energy and resultant sound intensity.
describe the biophysics of sound reception by the auditory system.
demonstrate how to measure various physical parameters of sound, with consideration of musical instrument and human voice production as well as auditory perception.
identify potential health risks of hazardous sound exposure to the auditory system and sound production of the vocal mechanism.
Table 1. Student Learning Outcomes.
Student Learning Outcomes.×
Students will be able to: describe basic physical and biophysical principles of sound generation.
explain how modification of physical parameters will impact sound generation in the context of musical instrument and human voice production.
describe the relationship between applied energy and resultant sound intensity.
describe the biophysics of sound reception by the auditory system.
demonstrate how to measure various physical parameters of sound, with consideration of musical instrument and human voice production as well as auditory perception.
identify potential health risks of hazardous sound exposure to the auditory system and sound production of the vocal mechanism.
×
Table 2. Course Projects.
Course Projects.×
Projects Tasks Core Concepts
Project 1: Physics of Musical instruments Build a stringed instrument (cigar box guitar) and a tube instrument (PVC pipe didgeridoo). Basic acoustics and musical acoustics, sound as vibration, physics of sound production and resonance, sound source as energy source.
Project 2: Electronic Sound Transducer Function & Use Interpretation of specification values for sound reinforcement equipment (microphones, loudspeakers, amplifiers). Sound as energy, transfer functions, analog to digital conversion, digital file compression.
Project 3: Digital Music Player Function & Use Exploration of functional parameters and potential hearing health risks with various headphones and earphones as connected to personal digital music players. Analog to digital conversion, digital recording and data compression, introduction to hearing health risk.
Project 4: Sound Level Measurement Investigation of functional parameters of sound measurement devices (standalone sound level meters & smartphone-based sound level meter apps). Sound as energy, sound pressure and sound power, inverse square law applied to sound propagation, sound level measurement.
Project 5: Acoustic Environments & Sound Exposure Measure sound pressure levels of a live amplified band in a controlled environment (recording studio). Sound as energy, effects of acoustic environments on sound level measurement and exposure.
Project 6: Hearing Health Risks & Injury Prevention Assess personal hearing status and interpret results with focus toward monitoring hearing status, selection, and measurement of hearing protector devices based on performance characteristics. Sound as energy that can potentially be damaging, hearing and hearing protector fit assessment and interpretation, hearing health risk and preventive strategies
Project 7: Voice Health Risks & Injury Prevention Investigation and assessment of vocal production characteristics. Identify risk factors for vocal damage. Sound as energy relative to the vocal folds as source of vibration, vocal health risk and injury prevention.
Project 8: Final Presentation Expansion on a previous project culminating in in-class presentation. Any core concepts may be revisited.
Table 2. Course Projects.
Course Projects.×
Projects Tasks Core Concepts
Project 1: Physics of Musical instruments Build a stringed instrument (cigar box guitar) and a tube instrument (PVC pipe didgeridoo). Basic acoustics and musical acoustics, sound as vibration, physics of sound production and resonance, sound source as energy source.
Project 2: Electronic Sound Transducer Function & Use Interpretation of specification values for sound reinforcement equipment (microphones, loudspeakers, amplifiers). Sound as energy, transfer functions, analog to digital conversion, digital file compression.
Project 3: Digital Music Player Function & Use Exploration of functional parameters and potential hearing health risks with various headphones and earphones as connected to personal digital music players. Analog to digital conversion, digital recording and data compression, introduction to hearing health risk.
Project 4: Sound Level Measurement Investigation of functional parameters of sound measurement devices (standalone sound level meters & smartphone-based sound level meter apps). Sound as energy, sound pressure and sound power, inverse square law applied to sound propagation, sound level measurement.
Project 5: Acoustic Environments & Sound Exposure Measure sound pressure levels of a live amplified band in a controlled environment (recording studio). Sound as energy, effects of acoustic environments on sound level measurement and exposure.
Project 6: Hearing Health Risks & Injury Prevention Assess personal hearing status and interpret results with focus toward monitoring hearing status, selection, and measurement of hearing protector devices based on performance characteristics. Sound as energy that can potentially be damaging, hearing and hearing protector fit assessment and interpretation, hearing health risk and preventive strategies
Project 7: Voice Health Risks & Injury Prevention Investigation and assessment of vocal production characteristics. Identify risk factors for vocal damage. Sound as energy relative to the vocal folds as source of vibration, vocal health risk and injury prevention.
Project 8: Final Presentation Expansion on a previous project culminating in in-class presentation. Any core concepts may be revisited.
×
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