Frequency & Hearing Demographics

This topic submitted by Thad Kerosky, Alex Melamed, Florence Heinen, Dylan Daney ( kerosktd@muohio.edu, melameaw@muohio.edu, heinenf@muohio.edu, daneydy@ ) on 10/10/03 .

We want to find that link to the whole range of sound, and preferably with good speakers, play if for the class to hear which ranges are bad and good. Maybe we could use the auditorium in boyd.
- Google:NCH-Tone-generator is a good canidate for play.
It would be good to find a java or flash app which illustrates frequency and power in the form of a simple sine wave.

Sound is something that is all around us. It is part of our everyday life yet few of us can explain what it is in precise words. Sound can be described as a wave which is created by vibrating objects and propagated through a medium from one location to another (The Nature of a Wave 2001). The medium is simply the material through which the wave is moving; it can be thought of as a series of interacting particles. The example of a slinky is often used to illustrate the nature of a wave. A disturbance is typically created within the slinky by the back and forth movement of the first coil of the slinky. The first coil becomes disturbed and begins to push or pull on the second coil; this push or pull on the second coil will displace the second coil from its equilibrium position. As the second coil becomes displaced, it begins to push or pull on the third coil; the push or pull on the third coil displaces it from its equilibrium position. This process continues in consecutive fashion, each individual particle acting to displace the one next to it; subsequently the disturbance travels through the slinky. As the disturbance moves from coil to coil, the energy that was originally introduced into the first coil is transported along the medium from one location to another (The Nature of a Wave 2001). A sound wave cn be said to form in much the same manner. The vibrating object which creates the disturbance in this case could be the vocal chords of a person or the vibrating string and sound board of a guitar for example.

There are three main types of waves, longitudinal, transverse, and surface waves. A transverse wave is a wave in which particles of the medium move in a direction perpendicular to the direction which the wave moves. A longitudinal wave in which particles of the medium move in a direction parallel to the direction which the wave moves.

_{(Diagram from The Nature of a Wave)}

The third type of wave, a surface wave, is the waves that travel along the surface of the oceans are referred to as surface waves. A surface wave is a wave in which particles of the medium undergo a circular motion. Surface waves are neither longitudinal nor transverse. In longitudinal and transverse waves, all the particles in the entire bulk of the medium move in a parallel and a perpendicular direction relative to the direction of energy transport. In a surface wave, it is only the particles at the surface of the medium which undergo the circular motion. The motion of particles tends to decrease as one proceeds further from the surface (the Nature of a Wave 2001)

_{(From The Nature of a Wave)}

In this project we will be using sine waves which are a type of transverse wave. Since a sine wave has only a single frequency associated with it, it may be considered the simplest sound (Sine Wave 1999). Frequency (λ) refers to the number of pressure peaks that pass a particular point in a space over a period of a second (Sound Waves 2002). The amplitude refers to the difference between maximum and minimum pressure (Sound, The Fundamentals 1999).

_{(From Sound Waves)}

The unit of frequency used for sound is Hertz (Hz) which has a periodic interval of one cycle per second. The human ear is able to feel frequencies between 20 Hz to 20 000 Hz, depending on the age of the person. Sound waves with a frequency above 20 000 Hz are called ultrasonic waves (Basic of Sound Waves 2001.

Hearing Physiology

The human ear is a very complicated organ. It is separated into three parts all of which play a role in how we as humans detect sound or hear. The three parts are the outer, middle, and inner parts. The outer ear is made of the pinna (the name for the parts the protrude from the head), the ear canal, and the tympanic membrane (eardrum) (Octicon 2003). These parts are largely cartilaginous and are the only visible parts of the ear. The outer ear.s function is to funnel sound in toward the tympanic membrane and protect the more delicate parts that they conceal (Advanced Cochlear Systems 2001).

The middle ear is made up of the tympanic cavity and includes the malleus, incus, and stapes, also known as the hammer, anvil, and stirrup. These three very little bones are known as ossicles. They vibrate together as a chain and amplify vibrations that transfer to the inner ear. The middle ear is also connected to the Eustachian tubes, which connect to the back of the throat to adjust pressure and allow for drainage.

The stapes tap against the inner ear, which is made up of the cochlea. The cochlea is an organ that is less than a centimeter wide at the base and about half a centimeter tall. It is made up of a tube about two millimeters wide that wraps around the cochlear nerve two and a half times. This snail shaped organ transforms signals in the form of vibrations to signals that the brain can understand and transmits them through the cochlear nerves.

There is fluid in the cochlea that carries the vibrations from the ossicles to a membrane on the inner wall of the cochlea. The distance from where the stapes makes contact changes what frequencies can be detected. Vibrations nearer to 20 Hz hit the membrane closer to the end and 20 000 Hz near to wide or apical end of the cochlea (CIRC 2002). This is at the heart of hearing loss because very loud sounds characterized as over 125 dB of a certain frequency can disable the ability to detect that sound in that range. This is due to damage to inner and outer hair cells that line the inside of the cochlea. There are many kinds of cells that make up the walls of this organ and would demand a book to describe.

The journey of a detectable sound goes as follows: first, the compression wave is funneled by the outer ear. Then the air molecules hit the eardrum that transfers the vibration to the ossicles, which amplify it and transfer it to the liquid inside the cochlea where cochlear nerves transplant the sound to the brain to be interpreted. Over time, one's ability to detect sounds may deteriorate. This may be represented in a loss of ability to hear certain frequencies or a decrease in the overall range from their original capacity.

Hearing Loss

Hearing loss occurs within the human population for a variety of reasons. Aging, drug treatments or physical injuries to the head are all causes of hearing loss. The most common type of hearing loss is caused by excessive noise. This can come from the workplace or recreation. Simply going to a rock concert exposes the ears to about 125 dB of sound (American Academy of Family Physicians 2000). Occupational hearing loss is currently recognized in both the United States and Canada as being within the top ten occupational diseases. Approximately 11 Million workers are being exposed to Occupational hearing loss on a yearly basis at American jobs (Ahmed 2001). In the United States alone the estimated health cost for hearing loss is at $200 million dollars (Ahmed 2001).

Beyond hearing loss caused in the work place hearing loss caused by recreation, specifically listening to music at excessive volumes. At least 15% of American teenagers have permanently lost some hearing. That.s about the same percentage you would find among people between 45 and 65 (Sherman 2000). As exposure is prolonged to excessive decibel levels of sound . the nerves and delicate membranes in the inner ear become damaged causing a hearing loss in the higher tones.(American Academy of Family Physicians 2000). This can cause an individual to be unable to hear most frequencies above 3,000 Hertz. (Hellstrom 1995). Hearing loss can severely alter speech ability. Acquisition of language skills and understanding speech patterns can be delayed by hearing loss (Schoenweiler 1998). The loss of ability to hear high frequency sounds can disrupt the comprehension of speech in accordance with an individual's sensitivity (Hearing Loss 2000). An individual's sensitivity in regards to hearing can be measured by calculating the range of frequencies an individual is able to perceive.

Audio and Computers

We will use computer generated sounds to perform our test of frequency ranges. Computers make sound differently than regular electronics. Computers only understand two states, on or off. This requirement of binary representation forces sound be broken down into incremental instantaneous measurements so the computer can process and understand. (Digital Audio Restoration 2001) Digital sound is generally considered harsher but is more accurate and analog sound is generally considered warmer but is noisier (Prichard, 2000). Using Digital Sound will enable us to get us the most accurate results when collecting data from the students of Peabody.

Hypothesis

We Hypothesize that there will be a negative correlation between hearing range and the amount of loud music the participants listen too. Furthermore, we think that there may be a statistical difference between men a women, those who have a history of high fever, and those of different ages.

we need to add reasons why there will be a difference?

Relevance

In the beginning, we set out to quantify any appreciable statistical trends within gender, age, hearing history, and music listening habits with respect to hearing range.

In researching for this project, we found an abundance of articles relating to occupational hearing loss. We also noted a lack of articles regarding hearing loss due to recreation. Using our survey, we expect to be able to identify individuals who regularly submit themselves to excessively loud music. If a correlation can be determined between hearing loss and the practice of listening to loud music our study will suggest greater attention be given to this issue by legislators, music equipment manufacturers, and performers. Our study would also evoke increased interest amongst the students of Peabody in regards to preserving their hearing abilities.

Any empirical evidence we derive from this research will be useful in situations where exact sound recognition is necessary. It would be possible to determine, for instance, how many residents in Peabody will be hearing a particular local band's music in it's complete frequency range production or the subset thereof.

Methods

We will likely test the hearing range of Peabody residents in their dorm rooms. This is to ensure that we have enough of a sample base to balance for the large number of classes we are analyzing for. The volunteers will be informed that they are going to get a 5 minute hearing test for our research. We hope to gather at least 30 male and 30 female subjects from around western. We will reduce external noise as much as possible by using noise-canceling headphones.

By hearing range we mean which frequencies between 20 Hz to 20 kHz that can be heard at the same decibel level. The range of frequency will be broken into increments of 500Hz and played over headphones by a computer. After filling out our survey concerning their demographics, the participant will put on the headphones and interact with a computer program or a member of the group. The frequency range test will involve either a random sound frequency being played or a blank pause a total of 45 times. The volunteer will indicate whether he or she has heard the sound (or perceived the blank time) by choosing one of two buttons on the computer monitor.

It is understood that people may say they have heard a sound when they have not for any number of reasons, so the "blank" dummy factor will be included in the series of sounds. A blank or time of no sound will replace one or some of the times when a sound is normally heard. This is to ensure that people do not just say yes, I hear it, to every question, or if they do, we will know there is a flaw in the survey. It will help us have a better statistical accuracy by possibly eliminating or making us aware of a possible source of inaccuracy.

With the data collected, we will be able to make correlations between many factors. Gender, age, hearing history, and music listening habits will all be considered. We will do an ANOVA test followed by a post-hoc analysis.

Questionnaire

Gender: Male Female

Age: ___ years

Do you have any known hearing problems? Yes / No

Have you ever had any accident which did/could have impaired your hearing? Yes No

Do you listen to loud music? Yes / No

If yes how many times per week? 1-3 4-6 7-10 10 or more

When you listen to music do you use headphones? Yes / No

If yes how many times per week? 1-3 4-6 7-10 10 or more

Have you ever been hospitalized for fever? Yes / No

How many concerts have you attended in the year? #_________

Results

Data Formatting Spec

Comma separated list, flexible to use with JMP and Excel.

Gender
Age
History of hearing.
Music Habits
Columns 5 - 45 Frequencies 20hz - 20000hz with apx. 500hz intervals--Yes/No.
Total Blanks/False Alarms

_{Due to the large amount of data collected from each participant it is not particularly feasible to turn in an entire spreadsheet this large. This is the same information presented slightly differently.}

Discussion

Works Cited

Hearing: Noise Induced Hearing Loss. 2000. American Academy of Family Physicians. http://familydoctor.org/handouts/226.html

The Annals of Occupational Hygiene Volume: 45, Issue: 5, July, 2001. pp. 371-380. Ahmed, H.O.; Dennis, J.H.; Badran, O.; Ismail, M.; Ballal, S.G.; Ashoor, A.; Jerwood, D.

International Journal of Pediatric Otorhinolaryngology Volume: 44, Issue: 3, August 10, 1998. pp. 251-258. Sch�nweiler, R.; Ptok, M.; Rad�, H.-J.

Hearing Research Volume: 88, Issue: 1-2, August, 1995. pp. 54-60. Hellstr�m, Per-Anders

Eric K. Prichard. May 15, 2000. Electronic Engineering Times. Is Audio Thin, Stiff, Dead or Warm, Fat, and Resilient.

Early Music America. 2000. http://homepages.kdsi.net/~sherman/hearingloss.htm Bernard D. Sherman

Hearing Loss. 2000. http://depts.washington.edu/hearing/Hearing%20Loss.html University of Washington.

Sound waves (2002). Cited: 9 October, 2003. http://members.optushome.com.au/scottsoftc/Chapter01/Chapter1c.htm

Sound, The Fundamentals (2003). Cited: 8 October, 2003. http://www.squ1.com/sound/properties.html

The Nature of a Wave (2001). Cited: 9 October, 2003. http://www.glenbrook.k.12.il.us/gbssci/phys/Class/waves/u10l1a.html

Sine Wave (1999). Cited: 7 October, 2003. http://www.sfu.ca/sonic-studio/handbook/Sine_Wave.html

Basics of Sound Waves (2001). Cited: 9 October, 2003 http://www.particle.kth.se/~fmi/kurs/PhysicsSimulation/Lectures/04A/waveSound.html

Oticon (2003). Cited: October 9, 2003. How does the ear work? www.oticon.dk.

Centre R�gional d.lmagerie Cellulaire (CRIC) (2002). Cited: October 9, 2003. Ear. http://www.iurc.montp.inserm.fr/cric/audition/english/ear/fear.htm

Advanced Cochlear Systems (2001). Cited: October 9, 2003. Hearing Physiology. http://www.inceptiongroup.com/advcoch/I2_Hearing_Physiology.htm

Jeff Welty (2001). Cited: October 9, 2003. Digital Audio Restoration.
http://gwc.sourceforge.net/gwc_science/gwc.html

Works Referenced (Bibliography)

Hearing: Noise Induced Hearing Loss. 2000. American Academy of Family Physicians. http://familydoctor.org/handouts/226.html

The Annals of Occupational Hygiene Volume: 45, Issue: 5, July, 2001. pp. 371-380. Ahmed, H.O.; Dennis, J.H.; Badran, O.; Ismail, M.; Ballal, S.G.; Ashoor, A.; Jerwood, D.

International Journal of Pediatric Otorhinolaryngology Volume: 44, Issue: 3, August 10, 1998. pp. 251-258. Sch�nweiler, R.; Ptok, M.; Rad�, H.-J.

Hearing Research Volume: 88, Issue: 1-2, August, 1995. pp. 54-60. Hellstr�m, Per-Anders

Early Music America. 2000. http://homepages.kdsi.net/~sherman/hearingloss.htm Bernard D. Sherman

Hearing Loss. 2000. http://depts.washington.edu/hearing/Hearing%20Loss.html University of Washington.

Sound waves (2002). Cited: 9 October, 2003. http://members.optushome.com.au/scottsoftc/Chapter01/Chapter1c.htm

Sound, The Fundamentals (2003). Cited: 8 October, 2003. http://www.squ1.com/sound/properties.html

The Nature of a Wave (2001). Cited: 9 October, 2003. http://www.glenbrook.k.12.il.us/gbssci/phys/Class/waves/u10l1a.html

Sine Wave (1999). Cited: 7 October, 2003. http://www.sfu.ca/sonic-studio/handbook/Sine_Wave.html

Basics of Sound Waves (2001). Cited: 9 October, 2003 http://www.particle.kth.se/~fmi/kurs/PhysicsSimulation/Lectures/04A/waveSound.html

Oticon (2003). Cited: October 9, 2003. How does the ear work? www.oticon.dk.

Centre R�gional d.lmagerie Cellulaire (CRIC) (2002). Cited: October 9, 2003. Ear. http://www.iurc.montp.inserm.fr/cric/audition/english/ear/fear.htm

Advanced Cochlear Systems (2001). Cited: October 9, 2003. Hearing Physiology. http://www.inceptiongroup.com/advcoch/I2_Hearing_Physiology.htm

Jeff Welty (2001). Cited: October 9, 2003. Digital Audio Restoration. http://gwc.sourceforge.net/gwc_science/gwc.html

Wikipedia (2003) Cited: October 9, 2003/ Digital Audio.
http://www.wikipedia.org/wiki/Digital_audio

For Further Info on this Topic, Check out this WWW Site: http://western.thadk.net/page/User:Kermit/NSProject . Next Article
Previous Article
Return to the Topic Menu

Here is a list of responses that have been posted to this Study...

Important: Press the Browser Reload button to view the latest contribution.

Respond to this Submission!

IMPORTANT: For each Response, make sure the title of the response is different than previous titles shown above!

DOWNLOAD the Paper Posting HTML Formating HELP SHEET!

We also have a GUIDE for depositing articles, images, data, etc in your research folders.

Article complete. Click HERE to return to the Pre-Course Presentation Outline and Paper Posting Menu.

Visit the rest of the site!

Site NAVIGATION--Table of Contents

Listen to a "Voice Navigation" Intro! (Quicktime or MP3)

WEATHER & EARTH SCIENCE RESOURCES

OTHER ACADEMIC COURSES, STUDENT RESEARCH, OTHER STUFF

| Educational Philosophy | Discovery Labs: Moon, Geologic Time, Sun, Taxonomy, Frisbee | Project Dragonfly | Vita |Field Course Postings | Student Research Postings | Nature/Science Autobiography | Environmental Programs at Miami University

TEACHING TOOLS & OTHER STUFF

Daily Necessities: Macintosh Resources |Search Engines | Library Resources|Server Stats| Family Album | View My Schedule | View Guestbook | Western College "Multimedia Potpourri"