A collection of the work of Mead Killion, PhD. This is all free for you to research, read and if you can use it for your own work, just make sure to credit him.
Click on the link below each title to view the file in Dropbox. You can also download the file from that page. You do not need a Dropbox account to view or download the files.
Hear for a Lifetime, Vandercook College of Music
January 26, 2024, Chicago, IL
How musicians can reduce the risk of hearing damage — all too common years ago among musicians. Comments from well-known musicians.
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To see the HEAR FOR A LIFETIME 2009 Lecture video described in slide #14), click on the video below.
HEAR FOR A LIFETIME, Vandercook College of Music, 2009 Lecture Video
Video explaining the advantages of the Companion Mics™ Design
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Killion (2018) SNR loss vs. Pure-Tone Audiometric loss and other things
The Inaugural Lecture of the Mead Killion Annual Lecture Series for the American Auditory Society, March 5, 2020, Scottsdale, AZ
Problems Understanding Speech in Noise: Measurement, Prevention and Mitigation
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Killion ASA talk on CMICS: New Improvements to the Latest 9-year-old Companion Mics System
From Acoustical Society of America (ASA) Talk, Chicago Meeting, May 8
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Myths that discourage Improvements
Myths in listening test truths
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Basilar membrane motion video
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Something About Mead – CanadianAudiologist.com
The Canadian Audiologist dedicated the entire last issue of 2025 to Mead Killion, featuring a loving tribute from long-time colleagues, as well as an archive of many of his articles published through the years at the publication. Click below to read the tribute and browse the large collection of articles.
Something about Mead
Dr. Mead Killion passed away comfortably on November 3, 2025 but he was aware of this issue of CanadianAudiologist.ca celebrating his life and accomplishments. Despite his passing, clinicians and researchers will continue to see “something about Mead” in their work for many years to come.
This issue of CanadianAudiologist.ca is dedicated not only to Dr. Mead Killion’s life’s accomplishments, but also to his work supporting and teaching others. This issue is called “Something about Mead” …
Mead’s Article Archive Published on etymotic.com
Compression: Distinctions, Mead C. Killion, Hearing Review, 3(8), 29, 30,32, 1996
Compression can mean different things to different people however there are many different technologies that can be labelled “compression” in the hearing aid industry. In this article, distinctions in meaning are explained regarding: Compression vs. AGC, Compression Limiting vs. Wide-Dynamic Range Compression (WRDC), TILL (Treble Increases at Low Levels) vs. Multichannel Compression, Multichannel Equalization vs. Multichannel Detection vs. Multichannel Signal Processing/Compression, Nonlinear Distortion vs. Nonlinear Amplifiers, Compression Ratio vs. Low Level Gain Increase, Input vs. Output compression, and WDRC+Linear vs. WDRC+Limiting.
CORFIG and GIFROC: Real Ear to Coupler and Back, Mead C. Killion and Lawrence J. Revit, In Acoustical Factors Affecting Hearing Aid Performance, (2nd edition), Studebaker, G.A., and Hochberg, I. (eds.) University Park Press, 65-86., 1993.
The acronym “CORFIG,” as used to describe the transformation that predicts the 2-cc coupler response of a hearing aid should have to provide a given insertion response, has gained a certain acceptance since the original version of this chapter was written 10 years ago. Whether or not its arithmetic inverse, “GIFROC,” will gain similar acceptance remains to be seen, but the basic utility of the transformation from real-ear to 2-cc coupler measurements (and vice versa) is well established. …We are now at the point where the first-order corrections are well known, and it is possible to concentrate on second-order effects and refinements.
Amplification: Is class D better than class B, Bill Johnson, Mead Killion ASHA, American Journal of Audiology, March 1994
During the analog days of audio processing the type of power amplifier had a heavy influence on battery life. The rule of thumb for HA designers was you needed to get one week of use from a single zinc-air cell. In addition to class B and D amplifiers the class A amplifier was quite commonly used for milder losses, but its low efficiency made it prone to clipping since we could never “bias” it with enough current to get high output levels. The H-bridge output transistor configuration, used in class D receivers, can still be found in all of today’s DSP based products. Today, the modulation of the high frequency switching is done digitally rather than the analog technique used when this article was written.
Earmold options for wideband hearing aids, Mead C. Killion, Journal of Speech and Hearing Disorders, 46, 10-20. 1981.
I actually didn’t need to go back to this article because I have memorized it by heart. Using knowledge of “quarter wavelength resonators” and the “acoustic transformer effect” (also known as the “horn effect” Mead was able to show the improved high frequency sound transmission of a number of earmolds that any earmold manufacturer could make. Among them was the most important (and commonly used in the 1980s and beyond) was the 8CR which stood for an earmold that extended the bandwidth of the hearing aid up to 8000 Hz and also re-established the 2700 Hz ear canal resonance (or as Mead would encourage us to write “earcanal” as one word). This became the standard for virtually all of my patients. The 8CR earmold introduced us to the use of acoustic filters where a judicious use of both 680 ohm and 1500 ohm filters resulted in a smooth frequency response. Of special importance in this article (which was a summary of the acoustics part of Mead’s PhD studies) was his Appendix. The Appendix (along with Robyn Cox’s 1979 monograph) could be the basis of any earmold acoustics course, and indeed did function as that.
The case of the missing dots: AI and SNR* loss, Mead C. Killion and Laurel A. Christensen, The Hearing Journal, 51(5), 32-47, 1998.
*Annotator’s note: In this paper, “AI” refers to Articulation Index, and “SNR” refers to Speech-to-Noise Ratio.
We used a simple Count-the-Dots approach to estimate the loss of information flow accompanying a given amount of SNR loss at low and high frequencies. Not only does this method nicely predict the reduced slope in the graph of percentage correct vs. SNR for hearing-impaired subjects, but (it) helps explain how hearing-impaired persons with high-frequency loss—those who often have the greatest SNR losses—will often obtain the greatest benefit in noise from the use of high-performance directional microphones. In the experiment reported here, this benefit exceeded the previously predicted benefit by nearly 2 dB. For once, it appears, those who need the most help may receive the most benefit.
Response modifying earhooks for special populations, Mead Killion, and Donald Wilson, Audecibel, 34(4), 28-30, 1985
The term KBASS stands for Killion-Berlin Bass Amplified unobStructed Sound hearing aid- a bit of a stretch but I always just assumed that it stood for Killion Bass amplifying earhook. Mead was able to, using computer simulations and a few experiments, replace 75 mm of tubing length, one damper, and two filter chambers with very narrow diameter tubing of a short length and provide an earhook in an non-occluding configuration that could be used with any power hearing aid- typically 20 dB was lost from the hearing aid specification but one could still obtain up to 40 dB of low frequency insertion gain with an open hearing aid fitting. In this article, Mead and Wilson also describe earhooks for any behind the ear hearing aid that could create an amplification notch at 2000 Hz (“2-kHz notch-filter” earhook), and a very “high-pass” earhook that would provide no amplification below 3000 Hz.
Some protection is good; too much is not good The Parvum Bonum, Plus Melius Fallacy in Earplug Selection pp. 415-433. In Recent Developments in hearing instrument technology, 15th Danavox Symposium, 1993, Ed. Joel Beilin and Gert Jensen.
The Outline of this chapter includes four sections- why the ER15 is required by musicians; why most factory workers need more than 15 dB of attenuation (but not all); the problems with non-musicians’ earplugs for factory workers; and other solutions based on both the work of Elmer Carlson and Elliott Berger. Industrial strength forms of hearing protection attenuate the higher frequencies more than the lower frequencies essentially creating the equivalent of a high frequency (conductive) loss, with the loss of important speech sounds that contribute to speech clarity and some factory warning signals.
What special hearing aid properties do performing musicians require? Hearing Review, 16(2), 20-31, 2009.
In this article Mead reviews what was said almost 100 years ago by W.B. Snow in 1931 about speech and music fidelity and notes that very little has changed- a high fidelity hearing aid for speech is ALSO a high fidelity hearing aid for music- namely sufficiently wide bandwidth (although most of Mead’s subjects could not hear the difference between a 14 kHz bandwidth and a 5 kHz bandwidth), a sufficient dynamic range between the room noise ( low 40 dBA range and the highest level that can be transduced with minimal distortion), a sufficiently long recovery time from compression, and a relatively smooth frequency response. Most manufacturers adhere to these general guidelines in order to optimize their hearing aids for both speech and for music. Of great importance in this article (at least for me) are the listening ratings for both hard of hearing and normal hearing subjects (his Figure 2). Mead concluded that listening quality ratings for normal hearing subjects are similar to those with at least up to a moderate sensori-neural level and indeed this is consistent of many of the modern hearing aid fitting formulae that only prescribe one or two decibels of gain for higher level inputs that are characteristic of live music, especially at the ear of the performers up on stage.
Hearing Aids - Past, Present and Future: SNR Loss Comes of Age, Mead C. Killion, Ph.D. and Patricia A. Niquette, M.A., In 18th Danavox Symposium, 325-340, 2000.
The technology exists to give nearly every hearing-impaired individual the ability to carry on conversations in noisy environments such as restaurants and parties. With mild SNR loss, simply increasing audibility with amplification will be enough. With greater SNR loss, some form of directional or close-talking microphones will be required. In all cases, however, we need to know the extent of the SNR loss so we can:
- choose the appropriate technology (it makes no sense to give everyone with a given hearing loss an FM system just because some individuals with that audiogram need it),
- adequately counsel our patients about the degree of their difficulty and the problems they will encounter after the various levels of intervention have been adopted…
Development of a quick speech-in-noise test for measuring signal-to-noise ratio loss in normal-hearing and hearing-impaired listeners — Mead C. Killion, Patricia A. Niquette, Gail I. Gudmundsen, Lawrence J. Revit, and Shilpi Banerjee, Journal of the Acoustical Society of America, 116(4), Part 1., No. 10, 2395-2405, 2000.
Hearing aid wearers report that their biggest problem with their hearing aids is that of understanding speech in background noise, and consumer surveys polling approximately 80,000 households have consistently revealed consumer dissatisfaction with hearing aids in noisy environments. …Kochkin (2002) reported that only 30% of hearing aid wearers were satisfied with their hearing aids in noisy situations. This paper describes a shortened and improved version of the Speech in Noise (SIN™) Test (Etymotic Research, 1993). In the first two of four experiments, the level of a female talker relative to that of four-talker babble was adjusted sentence by sentence to produce 50% correct scores for normal-hearing subjects. In the second two experiments, those sentences-in-babble that produced either lack of equivalence or high across-subject variability in scores were discarded. These experiments produced 12 equivalent lists, each containing six sentences, with one sentence at each adjusted signal-to-noise ratio of 25, 20, 15, 10, 5, and 0 dB. Six additional lists were also made equivalent when the scores of particular pairs were averaged. The final lists comprise the “QuickSIN” test that measures the SNRs a listener requires to understand 50% of key words in sentences in a background of babble. The standard deviation of single-list scores is 1.4 dB SNR for hearing-impaired subjects, based on test-retest data. A single QuickSIN lists takes approximately one minute to administer and provides an estimate of SNR loss accurate to +/-2.7 dB at the 95% confidence level.
Comparison of two hearing aid receiver-amplifier combinations using sound quality judgments, Catherine Plamer, Mead Killion, Laura Wilber, William Ballad Ear and Hearing, December 1995
The study discussed in this paper was comparing a class A amplifier to a class D system, with the subjects rating the sound quality on a 100 point scale. What makes this paper interesting is that the subjects were also required to assign a dollar value to a particular rating. The dollar scale went from 0$ all the way up to $700. Keep in mind this was before DSP hearing aids were released! The sound quality rating results followed an expected pattern, and using coherence as a measure of distortion tracked the rating results quite well also. Not surprisingly, when they adjusted the Class A bias up to an appropriate value the differences vanished, which I think is a nice control. Lastly, they identified that every point on the 100 value sound quality scale was worth $6.75 US. Converting this to Canadian and bringing it up to today’s dollars we get $20 per point. I like how this paper connected user benefit to economic rewards.
Classifying automatic signal processors, Mead Killion, Wayne Staab, and Dave Preves Hearing Instruments, vol 41(8), 1990
Not unlike today’s DSP based HAs the height of the analog era featured a number of different approaches to try and overcome the challenges of hearing loss. The authors thought that a signal processing tree would help bring some order to the various marketing efforts involved in each of the schemes. At the time this was useful, but of course with a modern DSP HA one can configure pretty much mimic any of these behaviors.
An “acoustically invisible” hearing aid. Mead C. Killion, Hearing Instruments, 39 (10), 39-44, 1988.
This is an article on “translational research”- it describes the missing link between what the human auditory system requires and how to address it with technology. The article is in two parts: Part 1 consists of the problem with hearing aids, and Part 2 addresses the K-AMP solution. The K-AMP was a single channel hearing aid but which functioned with differing low frequency and high frequency compression detectors with differing time constants. For low level inputs, the hearing aid was linear but as the inputs became louder, there was a gradual (and mild) input compression applied to the signal (no more than 1.7:1) and as the input increased, the gain dropped to zero, perfectly replicating the open ear response for high level inputs. The K-AMP was also among the very first hearing aid to use the class D receiver. In modern jargon, one would consider the K-AMP to be the first successful WDRC hearing aid- something we all take for granted now. (And on a personal note- I would recommend that anyone take five minutes and (re)read this 2 page classic article, along with the acknowledgements section at the end. Mead recognized that his accomplishments were only made possible with cooperation from many others.)
Insertion Gain Repeatability versus Loudspeaker Location: You Want Me to Put My Loudspeaker W-H-E-R-E? Mead C. Killion and Lawrence J. Revit, Ear and Hearing, 8(5), Supplement, 68S-73S, 1987.
The traditional 0˚ (straight ahead) location of the loudspeaker during insertion gain measurements is a poor choice, based on theoretical considerations, from the standpoint of repeatability. In a series of experiments, we were able to demonstrate that a location 45˚ to the side, or 45˚ up and 45˚ to the side, provided a much more repeatable measurement of basically the same insertion gain response…
A low frequency emphasis non-occluding hearing aid, Mead Killion, Charles I. Berlin, and Linda Hood, Hearing Instruments,35(8), 30-34, 1984.
In 1928 G.W. Stewart took out a patent #1,692,317 that described acoustic wave filters and was able to show that, given sufficient acoustic mass, the 1000 Hz “tubing-related” resonance found in behind the ear hearing aids could be shifted down to the 500 Hz region. Using that, and his general acoustic knowledge, Mead and his colleagues constructed an acoustic network built into a behind the ear hearing aid shell with 75 mm of 1 mm inner diameter tubing, one 680 ohm damper, and 2 filter chambers such that there was indeed sufficient acoustic mass in order to shift the primary hearing aid acoustic coupling resonance down to 500 Hz. And despite the inherent low frequency roll-off of sound energy with venting, he was still able to generate 30 dB of low frequency gain (with sufficient output) in a non-occluding hearing aid (IROS fitting). This type of hearing aid was designed for those with a low frequency hearing loss but with relatively good hearing above 1000 Hz. For this first time, low frequency amplification could be obtained with a non-occluding fitting. This approach was the precursor to the KBASS earhook that could be used on any power aid in a behind the ear configuration.
An earplug with uniform 15-dB attenuation, Mead Killion, Ed DeVilbiss, and Jonathan Stewart The Hearing Journal, vol. 41 (5),14-17, 1988.
This article discusses the limitations of current forms (prior to 1988) of hearing protectors including modifications that have been used to make them more “musician-friendly”, including the use of venting. However, venting only minimizes the degree of low frequency attenuation, and if the vent is larger, a resonance (or amplification) can occur. The innovation of Elmer Carlson used a thin plastic diaphragm that acts like a compliance (C1) and this is coupled to the sound channel which acts as an acoustic mass (or acoustic inertance) (L1). And since C1 is about 5 times smaller than the C of the residual earcanal volume, this results in a 15 dB attenuation. When these values are set correctly, a 2700 Hz Helmholtz resonance is established that off-sets the loss of this real ear unoccluded (or unaided) resonance (REUR) of the earcanal, with the net result being an attenuation pattern that is parallel to the REUR curve, and therefore creating a flat or uniform hearing protector. Mead and his coauthors felt that this uniform attenuation form of hearing protection would be ideal for musicians as well as industrial workers who were exposed to industrial sound levels below 100 dBA (100-15 = 85 dBA).
Sound Exposures and Hearing Thresholds Of Symphony Orchestra Musicians, Royster, J.D., Royster, L.H., and Killion, M.C. Journal of the Acoustical Society of America, 89(6), 279-281, 1991.
Royster, Royster, and Killion used dosimetry to measure the weekly exposure of all musicians in the Chicago Symphony Orchestra. These results were compared with a pre-cursor to the current international standard (ISO R-1999), namely ISO 7029 (1984) and found to be in very good agreement, demonstrating that the effects of music exposure were similar to the effects of noise exposure. Using a 3 dB exchange rate, dosimeters were fit on 68 classical musicians and the Leq was measured for 15 hours during the work-week noise exposure (excluding practice and teaching time) and found that equivalent weekly exposures (Leq) ranged from 75 -95 dBA. The resulting audiograms revealed that these were in excellent agreement with ISO 7029. Of interest is that 52.5% of classical musicians demonstrated notched audiograms consistent with those found in their industrial colleagues with the left ear of violinists and violists being worse than their right ears due to the proximity of the instrument to the left ears.
A wideband miniature microphone, Mead Killion, Elmer Carlson Journal of the Audio Engineering Society, Vol 18(6), December 1970
This paper concerned the introduction of ceramic microphones into HAs. The magnetic mics being used at the time had lots of moving mass, which in addition to providing a poor frequency response, made them quite sensitive to vibrations. Ceramic microphones have a very high electrical impedance which demanded the inclusion of a FET transistor to buffer the sound pickup on its way to the rest of the HA circuitry. The use of a FET paved the way for the development of the electret condenser microphone featuring even better performance. Once the noise floor of a MEMS (Micro Electro Mechanical System – think silicon based system) microphone was reduced enough to compete with the very quiet electret ones, manufacturing benefits drove the movement to these devices. MEMS microphones have the least vibration sensitivity. This is important because in addition to the acoustic feedback we all know of, in BTE HAs, receiver vibration couples back to the microphone, creating vibrational feedback, limiting the maximum gain. From a historical perspective it’s also fun to see mention of Mercury and Silver batteries!
Probe-tube microphone assembly, Edgar Villchur and Mead C. Killion, Journal of the Acoustical Society of America, 57, 238-240, 1975.
A method of making in-the-ear probe-microphone measurements is described, using readily available equipment. The procedure is designed to make such measurements easier and safer than thy have been in the past. Probe-tube microphone measurements of sound pressures in the human ear can provide data of great value, but such measurements are not used routinely because of fear of injury to the subject. …A relatively simple and inexpensive method of making in-the-ear probe measurements is described.
Article #1: New insert earphones for audiometry, Mead C. Killion, Hearing Instruments, 35(7), 28, 1984. Article #2: Insert earphones for more interaural attenuation, Mead C. Killion, Laura A. Wilber, and Gail I. Gudmundsen, Hearing Instruments, 36(2), 34-36, 1985.
Article #1: This report describes two new insert earphones designed for use in subjective and objective audiometry. While not without limitations of their own, these new earphones are free from most of the limitations of traditional headphones.
Article #2: Masking presented to an ear with a moderate-to-severe conductive loss often will mask both ears simultaneously. One solution to this well-known masking dilemma has been to use an insert earphone instead of the traditional supra-aural headphone.
Transducers, Earmolds and Sound Quality Considerations, Mead C. Killion, In Acoustical Amplification for the Hearing Impaired: Research needs, Studebaker, G.A., and Bess, F., (eds.), 1982.
This chapter presents an argument for a shift in emphasis in hearing aid research. (The called-for “shift” includes discussions of: developments in subminiature components; tailoring frequency response through innovative earmold and other design considerations; the importance of sound quality.) The physical limitations to hearing aid performance have now been largely removed, and recent speech discrimination research provides excellent information on how to maximize the aided speech discrimination score for a given individual. Much less information is available on how to maximize the overall utility of the hearing aid for a given individual as he goes about his daily life. This is a multidimensional problem, and arguments for multidimensional research are offered.
About Mead Killion
Mead C. Killion, Ph.D., Sc.D.(hon)
Mead Killion is the founder of Etymotic Research, an R&D organization whose mission includes: 1) Helping people hear, 2) Helping people preserve their hearing, and 3) Helping people enjoy hearing. Dr. Killion has been Adjunct Professor of Audiology at Northwestern University for 36 years.
He holds two degrees in mathematics, a Ph.D. in audiology, and an honorary Doctor of Science degree from Wabash College. He has authored or coauthored 88 papers, 21 book chapters and 92 U.S. patents in the fields of acoustics and hearing aids His scientific papers have been cited 1800 times in the last five years. He recently taught a PhD Seminar at Northwestern University in Innovation, Patents, and Starting a Business. .
Mead ran 32 marathons before age 68, when it took too long and hurt! Now he just plays Pickle Ball and directs a small church choir (for 37 years).
These days, Mead is learning to fly a Piper Cub J3 airplane, which he owns with a partner. He also recently incorporated a new startup company MCK Audio, Inc. in pursuit of a 25 year quest for helping people hear much better in noise with Companion Mics®. What else is an eighty-year-old fellow to do?
Education
A.B., Mathematics, Wabash College, 1961
M.S., Mathematics, Illinois Institute of Technology, 1970
Ph.D., Audiology, Northwestern University, 1979
Sc.D.(hon), Wabash College
Employment
President MCK Audio, Inc. Sept 2019-now
CTO and Chairman of the ER Board 2000-2018 (Hired a CEO)
President, Etymotic Research, Inc. 1983-2000
Adjunct Professor of Audiology, Northwestern University, 1982-present
Adjunct Professor of Audiology, Rush-Presbyterian-St. Luke’s Medical Center, 1996-2005
Adjunct, Doctoral Faculty, The City University of New York, Graduate School and University Center
Ph.D. Program in Speech and Hearing Sciences, 1999-2006
Senior Engineer, Industrial Research Products, a Knowles Company, 1962-1983
Awards and Honors
Outstanding Contributions to hearing sciences and the continuing education of hearing instrument dispensers, International Hearing Aid Society, 1984
Harvey Fletcher Award in Technical Application, For research in hearing aids and earmolds which have provided improved amplification for hearing-impaired individuals, New York League for the Hard of Hearing, May 6, 1986
American Journal of Audiology: A Journal of Clinical Practice Editor’s Award, For the article of highest merit published in 1993, American Speech-Language-Hearing Assn., 1993
Honors of the Chicago Speech-Language-Hearing Assn., May, 1994
Contributions to the success of the Australian College of Audiology, May 15-17, 1997
Sc.D. (Honorary Doctor of Science), Wabash College, May 18, 1997
Dr. James B. Snow Jr. Award, For furthering advances in understanding hearing loss and developing more effective hearing aid technology that is making a difference in the lives of hard of hearing people, Self Help for Hard of Hearing People, June 15, 1998
Outstanding Hearing Conservationist Award, In recognition of noteworthy contributions to the profession, National Hearing Conservation Association, February 22, 2003
Samuel F. Lybarger Award for Achievements in Industry, In recognition of his distinguished career and pioneering contributions in research, teaching and clinical service within the field of hearing, American Academy of Audiology, April 3, 2003
2010 Safe-in-Sound Excellence in Hearing Loss Prevention Award for Innovation in Hearing
Loss Prevention in the Manufacturing Sector, February 24, 2010 by NIOSH and NHCA
American Auditory Society Lifetime Achievement Award, March 5, 2010
2020 American Auditory Society: Initial lecture in the new Killion Lecture Series
Professional Societies, reverse date order
Past President, American Auditory Society, 1996-1997
Past President, Midwest Acoustics Conference, 1970
Past President, Chicago Acoustical and Audio Group, 1968
Fellow, British Society of Hearing Aid Audiologists, 1998
Fellow, Acoustical Society of America 1990
Fellow, Audio Engineering Society 1979
Member, American Academy of Audiology, 1988
Board of Directors, VanderCook College of Music, Chicago, 2010
Avocations
Amateur jazz pianist, violinist, choir director, barbershop quartet singer
Sailing, Flying, Running (32 Marathons)
Published Papers
1. Killion MC (1967) “A low-noise two-wire condenser microphone preamplifier,” J. Audio Eng. Soc. 15, 163-169.
2. Killion MC and Carlson EV (1970) “A wideband miniature microphone,” J. Audio Eng. Soc. 18, 631-635.
3. Killion MC and Carlson EV (1974) “A subminiature electret-condenser microphone of new design,” J. Audio Eng. Soc. 22, 237-243.
4. Carlson EV and Killion MC (1974) “Subminiature directional microphones,” J. Audio Eng. Soc. 22, 92-96.
5. Villchur E and Killion MC (1975) “Probe-tube microphone assembly,” J. Acoust. Soc. Am. 57, 238-240.
6. Killion MC (1975) “Vibration Sensitivity Measurements on Subminiature Condenser Microphones,” J. Aud. Eng. Soc. 23, 123-128.
7. Killion MC (1976) “Noise of Ears and Microphones,” J. Acoust. Soc. Am. 59, 424-433.
8. Killion MC (1976) “Earmold Plumbing for Wideband Hearing Aids,” J. Acoust. Soc. Am. 59, 562(A) Available from Knowles Electronics, Franklin Park, IL.
9. Villchur E and Killion MC (1976) “Auditory Aid to Deaf Speakers in Monitoring Fundamental Voice Frequencies,” Proceedings of 1976 Conference on Systems and Devices for the Disabled, RA Foulds and BL Lund, eds. (Biomedical Engineering Center, Boston).
10. Killion MC (1978) “Revised estimate of minimum audible pressure: Where is the ‘missing 6 dB’?” J. Acoust. Soc. Am. 63, 1501-1508.
11. Killion MC and Studebaker GA (1978) “A-weighted equivalents of permissible ambient noise during audiometric testing,” J. Acoust. Soc. Am. 63, 1633-1635.
12. Knowles HS and Killion MC (1978) “Frequency Characteristics of Recent Broadband Receivers,” J. Audiological Technique 17(5), 86-99 and (7), 136-140.
13. Killion MC (1979) “Equalization filter for eardrum-pressure recording using KEMAR manikin,” J.Audio Eng. Soc. 27, 13-16.
14. Killion MC and Dallos P (1979) “Impedance matching by the combined effects of the outer and middle ear,” J. Acoust. Soc. Am. 66, 599-602.
15. Killion MC (1981) “Earmold options for wideband hearing aids,” J. Speech and Hearing Dis. 46, 10-20.
16. Killion MC and Tillman TW (1982) “Evaluation of high-fidelity hearing aids,” J. Speech Hearing Res. 25, 15-25.
17. Killion MC (1984) “New insert earphones for audiometry,” Hearing Instruments 35, No. 7, 28.
18. Killion MC, Berlin CI and Hood L (1984) “A low frequency emphasis open canal hearing aid,” Hearing Instruments 35, No. 8, 30-34.
19. Killion MC (1984) “Recent earmolds for wideband OTE and ITE hearing aids,” Hearing Journal 37, No. 8, 15-22.
20. Killion MC, Wilber LA and Gudmundsen GI (1985) “Insert earphones for more interaural attenuation,” Hearing Instruments 36, No. 2, 34-36.
21. Killion MC and Wilson DL (1985) “Response-modifying earhooks for special fitting problems,” Audecibel 34, No. 4, 28-20.
22. Killion MC (1985) “The noise problem, There’s hope,” Hearing Instruments 36, No. 11, 26-32.
23. Ballad WJ, Clemis JD and Killion MC (1986) “Clinical use of an insert earphone,” Annals Otology, Rhinology and Laryngology 95, No. 5, 520-524.
24. Killion MC and Revit LJ (1987) “Insertion Gain Repeatability versus Loudspeaker Location: You Want Me to Put My Loudspeaker W H E R E?” Ear and Hearing 8, No. 5 Supplement, 68S-73S.
25. Killion MC, Wilber LA and Gudmundsen GI (1988) “Zwislocki was right…” Hearing Instruments 39, No.1, 14-18.
26. Wilber LA, Kruger B and Killion MC (1988) “Reference thresholds for the ER-3A insert earphone,” J. Acoust. Soc. Am. 83, 669-676.
27. Zuercher JC, Carlson EV and Killion MC (1988) “Small acoustic tubes: New approximations including isothermal and viscous effects,” J. Acoust. Soc. Am. 83, 1653-1660.
28. Killion MC, DeVilbiss E and Stewart J (1988) “An Earplug With Uniform 15-dB Attenuation,” Hearing Journal 41, No. 5,14-17.
29. Killion MC (1988) “An acoustically invisible hearing aid,” Hearing Instruments 39, No. 10, 39-44.
30. Killion MC and Villchur E (1989) “Comments on ‘Earphones in Audiometry,’” [Zwislocki et al., J. Acoust. Soc. Am. 83,1688-1689(1988)],” J. Acoust. Soc. Am. 85 No. 4, 775-1778.
31. Berger EH and Killion MC (1989) “Comparison of the noise attenuation of three audiometric earphones, with additional data on masking near threshold,” J. Acoust. Soc. Am. 86, 1392-1403.
32. Killion MC (1990) “A high fidelity hearing aid,” Hearing Instruments 41, No. 8, 38-39.
33. Killion MC, Staab WJ and Preves DA (1990) “Classifying automatic signal processors,” Hearing Instruments 41, No. 8, 24-26.
34. Mueller HG and Killion MC (1990) “An easy method for calculating the articulation index,” Hearing Journal 43, No. 9, 14-17.
35. Killion MC (1991) “High fidelity and hearing aids,” Audio 75, No. 1, 42-44.
36. Royster JD, Royster LH and Killion MC (1991) “Sound exposures and hearing thresholds of symphony orchestra musicians,” J. Acoust. Soc. Am 89, No. 6, 2793-2803.
37. Killion MC (1992) “Elmer Victor Carlson: A lifetime of achievement,” Bulletin of the Amer. Aud. Soc. 17, No. 1, March, 10-13, 20.
38. McGee T, Kraus N, Killion M, Rosenberg R and King C (1993) “Improving the Reliability of the Auditory Middle Latency Response by Monitoring EEG Delta Activity,” Ear and Hearing 14, No. 2, 76-84.
39. Gatehouse S and Killion MC (1993) “HABRAT: Hearing Aid Brain Rewiring Accommodation Time,” Hearing Instruments 44, No. 10, 29-32.
40. Killion MC and Villchur E (1993) “Kessler was right-Partly: but SIN test shows some aids improve hearing in noise,” The Hearing Journal 46, No. 9, 31-35.
41. Killion MC and Fikret-Pasa S (1993) “The 3 types of sensorineural hearing loss: loudness and intelligibility considerations,” The Hearing Journal 46, No. 11, 1-4.
42. Killion MC (1994) “Why some hearing aids don’t work well!!,” The Hearing Review 1, No. 1, 40, 42-43.
43. Johnson WA and Killion MC (1994) “Amplification: Is class D better than class B?” American Speech-Language-Hearing Assn., 11-13.
44. Goode RL, Killion MC, Nakamura K and Nishihara S (1994) “New knowledge about the function of the human middle ear: development of an improved analog model,” The American Journal of Otology 15, No. 2, 145-154.
45. Killion MC (1994) “The effect of extended playing on the tone of new violins,” Catgut Acoustical Society Journal 2, No. 5, 22-23.
46. Killion MC (1994) “The adverse side effects of FDA’s hearing aid proscriptions,” Medical Device and Diagnostic Industry, No. 10.
47. Palmer CV, Killion MC, Wilber LA and Ballad WJ (1995) “Comparison of two hearing aid receiver-amplifier combinations using sound quality judgments,” Ear Hear 16, No. 6, 587-598.
48. Mueller HG and Killion MC (1996). “http://www.compression.edu,” The Hearing Journal, 49, No. 1, 10, 44-46.
49. Killion MC (1996) “Compression: Distinctions,” The Hearing Review, 3, No. 8, 29, 30, 32.
50. Killion MC (1996-97) “Good writing,” Bulletin of the American Auditory Society, 21, No. 3, 9, 17; 22, No. 1, 4, 25, 31; 22, No. 2, 4, 16.
51. Killion MC (1997) “A critique on four popular statements about compression,” The Hearing Review, 4, No. 2, 36, 38.
52. Ling D and Killion M (1997) “New versus old: Playing-in instruments through vibratory transmission of music to the bridge,” CASJ 3, No. 3 (Series II), May.
53. Killion MC (1997) “Guest Editorial: Hearing aids: Past, present, future: Moving toward normal conversations in noise,” British Journal of Audiology, 31, 141-148.
54. Killion MC (1997) “The SIN report: Circuits haven’t solved the hearing-in-noise problem,” The Hearing Journal, 50, No. 10.
55. Killion, MC (1997). “SNR Loss: “I can hear what people say, but I can’t understand them,” The Hearing Review, 4, No.12, 8-14.
56. Killion MC, Schulein R, Christensen L, Fabry D, Revit LJ, Niquette P and Chung K (1998) “Real-world performance of an ITE directional microphone,” The Hearing Journal, 51, No. 4, 24-38.
57. Killion MC and Christensen L (1998) “The case of the missing dots: AI and SNR loss,” The Hearing Journal, 51, No. 5, 32-47.
58. Christensen L, Killion MC, Niquette PT and Revit LJ (1998) “Some instructions to readers on using the Journal’s real-world audio CD,” The Hearing Journal, 51, No. 8, 68-75.
59. Killion MC (1999) “Stupendous and Earth Shattering?” Illinois Academy of Audiology Newsletter, Spring Issue.
60. Killion MC (1999) “Digital, Analogue, and Directional: Will the real winner please step forward,” British Society of Hearing Aid Audiologists Newsletter, Winter/Spring Issue.
61. Killion MC and Niquette PA (2000) “What can the pure-tone audiogram tell us about a patient’s SNR loss?” The Hearing Journal, 53, No. 3, 46-53.
62. Killion MC (2001) “Page 10: Digital cellphones and hearing aids: The problem is mostly solved,” The Hearing Journal, 54, No. 3, 10-19.
63. Killion MC (2001) “Digital Cellphone Progress Report,” British Society of Hearing Aid Audiologists News, May Issue.
64. Killion MC, Teder H and Thoma R (2001) “Suitcase Lab Measurement of Digital Cellphone Interference Levels on Hearing Aids,” J. Amer. Acad. Audiol., 12, No. 6, 281-285.
65. Killion MC (2002) “New Thinking on Hearing in Noise: A Generalized Articulation Index.” Paper based on a presentation at CID Conference on New Frontiers in the Amelioration of Hearing Loss, Seminars in Hearing, 23, No. 1, 57-75.
66. Christensen LA, Helmink D, Soede W and Killion MC (2002) “Complaints about hearing in noise: A new answer,” Hear. Rev. 9, No. 6, 34-36.
67. Killion MC (2003) “Earmold Acoustics,” Seminars in Hearing, 24, No. 4, 299-312.
68. Block MG, Tillman TW and Killion MC (2004) “The ‘Missing 6 dB’ of Tillman, Johnson, and Olsen was found – 30 years ago,” Seminars in Hearing, 25, No. 1, 7-16.
69. Killion MC (2004) “Myths that Discourage Improvements in Hearing Aid Design,” The Hearing Review, 11, No. 1, 32-40, 70.
70. Killion MC (2004) “Myths About Hearing in Noise and Directional Microphones,” The Hearing Review, 11, No. 2, 14-19, 72-73.
71. Killion MC (2004) “Myths about Hearing Aid Benefit and Satisfaction,” The Hearing Review, 11, No. 8, 14-20, 66.
72. Killion MC, Niquette PA, Gudmundsen GI, Revit LJ and Banerjee S (2004) “Development of a Quick Speech-in-Noise Test for Measuring Signal-to-Noise Ratio Loss in Normal-Hearing and Hearing-Impaired Listeners,a)” J. Acous. Soc. Am., 116(4), Pt. 1, No. 10, 2395-2405.
73. Compton-Conley CI, Neuman AC, Killion MC and Levitt H (2004) “Performance of Directional Microphones for Hearing Aids: Real-World Versus Simulation,” J. Amer. Acad. Audiol., 15, 440-455.
74. Killion MC and Gudmundsen GI (2005) “Fitting Hearing Aids Using Clinical Prefitting Speech Measures: An Evidence-Based Review,” J. Amer. Acad. Audiol., 16, 439-447.
75. Killion MC, Niquette PA, Gudmundsen GI, Revit LJ, and Banerjee S (2006) “Erratum:
‘Development of a quick speech-in-noise test for measuring signal-to-noise ratio loss in normal-hearing and hearing-impaired listeners’ [J. Acoust. Soc. Am. 116(4), 2395-2405 (2004)],” J. Acous. Soc. Am., 119(3), 1888.
76. Villchur EV and Killion MC (2008) “ Measurement of Individual Loudness Functions by Trisection of Loudness Ranges,” Ear and Hearing, 29(5), 693-703.
77. Killion MC (2009) “ What Special Hearing Aid Properties Do Performing Musicians Require?” The Hearing Review, 16(2), 20-31.
78. Killion MC (2009) “Comparison of vu-meter-based and rms-based calibration of speech levels,” J. Acous. Soc. Am., 126(3), EL97- EL99.
79. Killion MC and Mueller HG (2010): Twenty years later: A NEW Count-The-Dots Method The Hearing Journal, 63(1), 10-17.
80. Killion MC, Monroe T and Drambarean V (2011) “Better protection from blasts without sacrificing situational awareness,” Inter. J. Audiol. 50, S38-S45.
CDs and DVDs
Killion MC and Schulein R (1998) Audio CD accompanying the articles “Real-world performance of an ITE directional microphone” and “The case of the missing dots: AI and SNR loss,” The Hearing Journal, 51, Nos. 4 and 5.
Killion MC and Revit LJ (2001) Quick SIN Speech-in-Noise Test, Version 1.3.
Killion MC and Revit LJ (2001) BKB-SIN Test, Beta-2 Trial Version.
Killion MC (2003) DigiK Sound Quality Comparison of Digital Hearing Aids and More.
Book Chapters
1. Killion MC and Monser EL (1980) “CORFIG: Coupler response for flat insertion gain,” Chapter 8 in Acoustical Factors Affecting Hearing Aid Performance, Studebaker GA and Hochberg I, eds. (University Park Press, Baltimore).
2. Killion MC (1980) “Problems in the application of broadband hearing aid earphones,” Chapter 11 in Acoustical Factors Affecting Hearing Aid Performance, Studebaker GA and Hochberg I, eds. (University Park Press, Baltimore).
3. Killion MC (1982) “Transducers, earmolds and sound quality considerations,” Chapter in Acoustical Amplification for the Hearing Impaired: Research Needs, Studebaker GA and Bess F, eds.
4. Killion MC (1988) “Earmold Design: Theory and Practice,” Chapter II in Proceedings of 13th Danavox Symposium, Janne Hartveg Jensen, ed. (Stougaard Jensen, Copenhagen), p. 155-174.
5. Killion MC (1988) “Special Fitting Problems and Open-Canal Solutions,” Chapter III in Proceedings of 13th Danavox Symposium, Janne Hartveg Jensen, ed. (Stougaard Jensen, Copenhagen), p. 219-230.
6. Killion MC (1988) “The Hollow Voice Occlusion Effect,” Chapter III in Proceedings of 13th Danavox Symposium, Janne Hartveg Jensen, ed. (Stougaard Jensen, Copenhagen), p. 231-242.
7. Killion MC (1988) “Principles of High Fidelity Hearing Aid Amplification,” Chapter 3 in Handbook of Hearing Aid Amplification, Volume I: Theoretical and Technical Considerations, Sandlin RE, ed. (College-Hill Press, Boston), p. 45-80.
8. Killion MC (1993) “Transducers and Acoustic Couplings: The Hearing Aid Problem That Is (Mostly) Solved,” Chapter 3 in Acoustical Factors Affecting Hearing Aid Performance (2nd ed.), Studebaker GA and Hochberg I, eds., (University Park Press, Baltimore), p. 31-50.
9. Killion MC and Revit LJ (1993) “CORFIG and GIFROC: Real Ear to Coupler and Back,” Chapter 5 in Acoustical Factors Affecting Hearing Aid Performance (2nd ed.), Studebaker GA and Hochberg I, eds. (University Park Press, Baltimore), p. 65-86.
10. Killion MC (1993) “The K-AMP Hearing Aid: An Attempt to Present High Fidelity for the Hearing Impaired,” Chapter in Recent Developments in Hearing Instrument Technology, Beilin J and Jensen GR, eds. (15th Danavox Symposium, Denmark), p. 167-229.
11. Killion MC (1993) “The Parvum Bonum, Plus Melius Fallacy in Earplug Selection,” Chapter in Recent Developments in Hearing Instrument Technology, Beilin J and Jensen GR, eds. (15th Danavox Symposium, Denmark), p. 415-433.
12. Killion MC (1995) “Talking Hair Cells: What They Have to Say About Hearing Aids,” Chapter 8 in Hair Cells and Hearing Aids, Berlin CI, ed. (Singular Press, San Diego), p. 125-172.
13. Yost WA and Killion MC (1997) “Hearing Thresholds,” Chapter 123 in Vol. 3, Encyclopedia of Acoustics, Crocker MJ, ed., (John Wiley & Sons, Inc., New York, NY), p. 1545-1554.
14. Killion MC (1997) “Hearing Aid Transducers,” Chapter 166 in Vol. 4, Encyclopedia of Acoustics, Crocker MJ, ed., (John Wiley & Sons, Inc., New York, NY), p. 1979-1990.
15. Killion MC and Niquette P (1999) “Hearing Aids – Past, present, future: SNR loss comes of age,” Chapter in Proceedings of 18th Danavox Symposium (Copenhagen, Denmark), p. 325-340.
16. Killion MC and Christensen LA (2000) “Principles of High Fidelity Hearing Aid Amplification,” Chapter in The Textbook of Hearing Aid Amplification (2nd ed.), Sandlin RE, ed., (Singular Publishing Group, Inc., San Diego, CA), p. 171-207.
17. Killion MC (2006) “Research and Clinical Implications for High Fidelity Hearing Aids,” Chapter in Hearing Care for Adults, Palmer C and Seewald RC, eds., (Phonak AG), p. 181-191.
18. Killion MC and Villchur E (2007) “Hearing Aid,” Chapter in 10th Edition McGraw-Hill Encyclopedia of Science and Technology, April.
19. Killion MC (2007) “Hearing Loss and Hearing Aids: a Perspective,” Chapter in The Senses: A Comprehensive Reference, Elsevier Ltd., December.
Invited Presentations
Invited presentations and all-day workshops given in 19 countries.
Early U.S. Patents
1. Killion MC, Carlson EV and Burkhard MD (1970) “Audio Frequency Amplification Circuit,” U.S. Patent No. 3,512,100.
2. Carlson EV, Cross FW and Killion MC (1971) “Acceleration Insensitive Transducer,” U.S. Patent No. 3,577,020.
3. Carlson EV, Cross FW and Killion MC (1971) “Miniature Acoustic Transducer of Improved Construction,” U.S. Patent No. 3,588,383.
4. Carlson EV and Killion MC (1972) “Acoustic Transducer Having Diaphragm Pivoted in its Surround,” U.S. Patent No. 3,701,865.
5. Carlson EV and Killion MC (1973) “Diaphragm Assembly for Electret Transducer,” U.S. Patent No. 3,740,496.
System and Method,” Issuing after August.
Etymotic Research now has over 100 patents, including several on Companion Mics.