Thursday, December 07, 2006

The Microphone part 9

On to Modern microphones!

The big modern mic is the transducer mic.
In 1964, Bell Laboratories researchers James West and Gerhard Sessler received patent no. 3118022 for the foil electret microphone. This microphone offered greater reliability, higher precision, lower cost, and a smaller size. It revolutionized the microphone industry, with almost one billion manufactured each year.

West started at Bell labs as an intern and joined them full-time in 1957 after graduating from Temple University. As the inventor of the microphone, James West has received numerous awards and honors including a Fellow of IEEE, Industrial Research Institute's 1998 Achievement Award, 1995 Inventor of the Year from the State of New Jersey and induction in the Inventors Hall of Fame in 1999. James E. West holds 47 US patents and more than 200 foreign patents from his 40-year career with Bell Laboratories.

Laser Microphones are (duh) microphones that use a laser beam. They detect vibrations with a laser and convert it to a digital signal. Any object which can resonate/vibrate will do so in response to the pressure waves created by noises present in a room. The minute differences in the distance travelled by the light to pick up this resonance is detected Interferometrically. (ooh big word) It converts the variations in distance into intensity variations then the variations are converted to digital signals that can be interpreted as sound.

It was invented in baby steps. I wont get into it except to say that it probably starts in 1954, with Charles Townes and Arthur Schawlow inventing the maser. (The maser was invented before the laser.)