Audio Engineering Society Singapore Section

On Wednesday, 29 March 2000 at 7.00pm, 17 members and 20 guests of the AES Singapore Section gathered at Touch Community Theatre to attend a talk on “The History & Development of Condensor Microphones” by Dr Preston Murphy. Dr Murphy has been President of Lectret since its founding in Geneva in 1976, and in Singapore, 1987. Lectret Precision Pte Ltd, the Singapore based company, features a range of microphone products like headworn and lavaliere microphones for professional audio, lightweight headsets, noise reducing headsets and digitally enhanced microphones. Dr Murphy is a Life Charter Associate of the AES, and is a Member of the Acoustical Society of America.

Dr Murphy began his talk with the invention of the magnetic microphone in 1875 by A.G Bell and the carbon microphone in 1876 by T Edison. He briefly explained the mechanics of the different types of microphones, and gave a background to the features and applications of each type.

Going on to prepolarised/electret microphones, Dr Murphy told the audience that the foil electret microphone was invented in 1962 by Sessler and West of Bell Labs. Since then, the electret microphone, due to its characteristic insensitivity to vibration, thus less susceptible to noise, has grown in popularity, especially in “Walkman” recorder products. As early as the 1970s, companies like Matsushita and Lectret have taken the electret microphone into industrialisation, with Dr Murphy inventing the thermoelectron foil electret microphone in 1970.

Dr Murphy also talked about typical characteristics of microphones, such as the various directivity types, and the various frequency response shapes. He noted that frequency response of microphones were often boosted at the 3khz to 5khz region and rolled off at the low frequencies, for max speech intelligibility and noise rejection, a good example being in the application of hearing aids.
 

Dr. Preston V Murphy (right) with his wife, Mireille L Murphy (centre) chatting with the section Chairman, Mr. Jibby Jacob (left) - photograph by Robert Soo.

Talking about the microphone industry, Dr Murphy presented an amazing fact, that in the past records of Matsushita from 1970 to 1980, microphone production had increased by a whopping 30 million units, the cassette recorder being the main contributor. Today, the year 2000, production of microphones has topped 400 million units, owing its success mainly to the age of telecommunication and multimedia. He said that in today’s pro-audio market, microphones alone take a US$840m share, which is 7% of the total pro-audio market.

Dr Murphy was proud to share with us that Lectret microphones were OEMed to world reknowned audio manufacturers such as Audio-Technica and Crown. It was very interesting to note that Lectret microphones have been used by the Pope himself, by the secret service of the White House, and even by Madonna and Michael Jackson.

In a peek to the future, Dr Murphy provided some food for thought as to how new technologies would affect the life and growth of microphone technology. An eye-catching emerging technology is the optical microphone being developed presently by Sennheiser. One glaring fact is  that more and more digital technology will be applied to microphones in the coming years. The meeting ended with a question and answer session. The AES Singapore Section would like to thank Mr Robert Soo and his colleagues for the use of the community theatre and for their kind assistance during the meeting.

Section Chairman, Mr. Jibby Jacob (left) presenting a plaque to Dr. Preston Murphy (right) - photograph by Robert Soo.

Biography of Dr. Preston V. Murphy

 
Dr. Preston V. Murphy
Life Charter Associate Member, AES
President of Lectret Precision Pte Ltd, Singapore

Born in 1930 in East Chicago, Indiana, Dr Preston Murphy has been the President of Lectret since its founding in Geneva, 1976, and in Singapore 1987. He obtained his BSc from Notre Dame University in 1951 and PhD in Radiochemistry form Washington University, St Louis in 1956.  In 1964, he was the President and Chairman of Panoramic Research, Inc in Palo Alto, California, where his work involved the development of electret microphones. In 1965, he went on to join Thermo Electron Corporation in Waltham, Massachusetts, and later became the Director of Research.

His audio work includes numerous publications and patents on condenser, piezoelectric, silicon based transducers. Present company products are headworn and lavalier microphones for professional audio, lightweight headsets, noise reducing headsets and digitally enhanced microphones. He is a Life Charter Associate of the Audio Engineering Society (AES), and Member of the Acoustical Society of America.

Copyright 2000 AES Singapore Section