In This Section
- Acoustics and Sound Reinforcement
- Archiving Restoration and Digital Libraries
- Audio for Games
- Audio for Telecommunications
- Audio Forensics
- Automotive Audio
- Coding of Audio Signals
- Electro Magnetic Compatibility
- Fiber Optics for Audio
- Hearing and Hearing Loss Prevention
- High Resolution Audio
- Human Factors in Audio Systems
- Loudspeakers and Headphones
- Microphones and Applications
- Network Audio Systems
- Perception and Subjective Evaluation of Audio Signals
- Recording Technology and Practices
- Semantic Audio Analysis
- Signal Processing
- Sound for Digital Cinema and Television
- Spatial Audio
- Transmission and Broadcasting
AES Technical Committee
Hearing and Hearing Loss Prevention
Chair: Robert Schulein (Send Email) Vice Chair: Michael Santucci (Send Email) Vice Chair: Jan Voetmann (Send Email)
1. Raising AES member awareness of the normal and abnormal functions of the hearing process.
2. Raising AES member awareness of the risk and consequences of hearing loss resulting from excessive sound exposure.
3. Coordinating and providing technical guidance for the AES supported hearing testing and consultation programs at US and European Conventions.
4. Facilitating the maintenance and refinement of a database of audiometric test results and exposure information on AES members.
5. Forging a cooperative union between AES members, audio equipment manufacturers and the hearing the hearing conservation communities for purposes of developing strategies, technologies, and tools to reduce and prevent hearing loss.
Would you like to contribute?
If you are interested in participating in the committee's work please send an e-mail to the chair Robert Schulein. Please indicate in your e-mail that you are interested in the AESTC-HHLP. We welcome those interested in joining the committee to attend a future committee meeting. AES and non AES members are always welcome. Please Note: You do not have to be an AES member to join this committee, however you must be an AES member to serve as Chair or Vice-Chair of the committee. The committee communicates by means of an e-mail reflector site. This committee meets approximately evety 6 months at alternate European and US conventions.
Emerging Technology Trends
Current technology in the field of audiology allows for the primary measurement of hearing loss by means of:
1. Minimum sound pressure level audibility vs. frequency producing an audiogram record. Such a record is used to define hearing loss in dB vs. frequency.
2. Measurement of speech intelligibility masked by varying levels of speech noise. Such measurements allow individuals to compare their speech intelligibility signal-to-noise ratio performance to the normal population.
Other tests are commonly used as well for diagnosis as to the cause of a given hearing loss and as a basis for treatment. Within the past ten years, new tests have evolved for diagnosing the behavior of the cochlea by means of acoustical stimulation of hair cells and sensing their resulting motion. Minute sounds produced by such motions are referred to as otoacoustic emissions.
Measurement systems developed to detect and record such emissions work by means of distortion product detection resulting from two-tone stimulations as well as hair cell transients produced from pulse-like stimulations. Test-equipment design for such measurements are now in common use for screening newborn children. Additional research is being conducted directed at using such test methods to detect early stages of hearing loss not yet detectable by hearing-threshold measurements.
The AESTC-H&HLP is currently working to establish a cooperative relationship between researchers in this field and AES members, who will serve as evaluation subjects.
Currently there is no known cure for what is referred to as sensory neural hearing loss, in that irreparable damage has been done to the hearing mechanism. Such loss is commonly associated with aging and prolonged exposure to loud sounds, although it is well established that all individuals are not affected to the same degree. Considerable research is ongoing with the purpose of devising therapies leading to the activation of cochlear stem cells in the inner ear to regenerate new hair cells. There are however drug therapies being introduced in oral form to prevent or reduce damage to the cilia portion of hair cells in cases where standard protection is not enough, such as in military situations.
Hearing instruments are the only proven method by which sensory neural hearing loss is treated. In general the task of a hearing instrument is to
use signal processing and electroacoustical
means to compress the dynamic range of sounds in the real world to the now limited audible dynamic range of an impaired person. This requires the
implementation of level-dependent compression circuits to selectively amplify low-level sounds and power amplification and high-performance
microphone and receiver transducers fitted into miniature packages. Such circuitry is commonly implemented using digital signal processing techniques powered by miniature 1-volt zinc-air batteries.
In addition to dynamic-range improvements, hearing aids serve to improve the signal-to-noise ratio of
desired sounds in the real world primarily for better speech intelligibility in noise. Currently miniature directional microphone systems with port
spacings in the 5-mm range are being used to provide improvements in speech intelligibility in noise of 4 to 6 dB. Such microphones have become
rather sophisticated, in that many designs have directional adaptation circuits designed to modify polar patterns to optimize the intelligibility of desired sounds. In addition some designs are
capable of providing different directional
patterns in different frequency bands. Furthermore, some hearing aid manufacturers have introduced products using second-order directional
microphones operating above 1 kHz with some success.
In many situations traditional hearing aid technology is not able to provide adequate improvements in speech intelligibility. Under such circumstances wireless transmission and
reception technology is being employed to essentially place microphones closer to talkers mouths and speakers closer to listeners ears. This
trend appears to offer promise enabled by the evolution of smaller transmitter and receiver devices and available operating-frequency allocations. Practical devices using such technology are now being offered for use with cellular telephones. This is expected to be an
area of considerable technology and product growth.
Another hearing disorder, tinnitus, is commonly experienced by individuals, often as a result of ear infections, foreign objects or wax in the ear, and injury from loud noises. Tinnitus can be perceived in one or both ears or in the head. It is usually described as a ringing, buzzing noise or a pure tone perception. Certain treatments for tinnitus have been developed for excessive
conditions in the form of audio masking, however most research is directed toward pharmaceutical solutions and prevention. In Europe, psychological
assistance to help individuals live with their tinnitus is a well established procedure.
Hearing-loss prevention has become a major focus of the AESTC-H&HLP due to the fact that a majority of AES members come in contact with high-level
sounds as a part of the production, creation, and reproduction of sound. In addition, this subject has become a major issue of consumer concern due to the increased availability of fixed and portable audio equipment capable of producing damaging sound levels as well as live sound performance attendance. One approach to dealing with this issue is education in the form of communicating acceptable exposure levels and time guidelines. Such measures are however of limited
value, as users have little practical means of gauging exposure and exposure times. This situation represents a major need and consequent opportunity for the AESTC-H&HLP, audio equipment manufacturers, and the hearing and hearing-conservation communities.
Current and Future Activities
1. The TC is in the process of developing workshops and Tutorials for the 124 and 125 AES conventions in Amsterdam, The Netherlands, and San Francisco, CA.
2. The TC is in the initial stages of developing a proposal for an AES Conference with the working Title “Engineering Technology for Hearing Conservation and Sound Reproduction”.
3. The TC is looking for a research partner to study the relationship between individual Otoacoustic Emissions data and Hearing Threshold Data. We have identified a potential research partner and are now developing a research plan.
4. The TC is working on implementing a hearing screening and consultation program at the 126th AES Convention in Munich, Germany
5. The TC organized a "How Loud Do You Listen" test and demonstration in conjunction with the NHCA (National Hearing Conservation Association). This activity took place at the 121 AES Convention in San Francisco. We expect to have results from this test program by October of 2008.
Elizabeth Cohen Ivan Stamac Jan Voetmann Peter Mapp Richard S Stroud Robert Schulein William L Martens Bozena Kostek Ian Kuhn Laurie Wells Michael Santucci Scott Snyder Brian Fligor Marilee Potthoff Jeff Schwartz Benjamin Kanters Jason Corey Preben Kvist Waldo Nogueira Lawrence Revit Pam Gunn Beno Groothoff Jeanne Stiernberg Neil Cherian Jon Boley Keith Gordon J M Woodgate Marshall Chasin Ainslie Harris John Usher Gonzalo J. Rodriguez Christopher Struck Omatali Beckett Vicki Silver Benjamin Mesiti Michiel Van Eeden Joseph Blasingame Anton Schlesinger Colin Bigland Stephen Ambrose John Dawson Jan van Doorn Zhong Xuan Kathy Peck Kristin Bidwell Tom Fritsch Retnaguru Sandrakasan Dorte Hammershoi
To request membership in this Technical Committee please email the Chair by using the link above.