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.

Problems Understanding Speech in Noise: Measurement, Prevention and Mitigation – Lecture Slides

Killion, MC (2020): Inaugural lecture of the Killion Lecture Series for the American Auditory Society, March 5, Scottsdale, AZ
Click to view the PowerPoint presentation.
Click to view the video

Myths that discourage Improvements

Click to view the pdf.

Myths in listening test truths

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VanderCook College of Music lecture:  Hear for a lifetime

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Basilar membrane motion video

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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

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How musicians can reduce the risk of hearing damage — all too common years ago among musicians. Comments from well-known musicians.

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 Audiology, 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?


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


President MCK Audio, Inc. Sept 2019-now
Advisor to Etymotic/Lucid 2018-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


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.

© 2020. Mead Killion. All Rights Reserved.