DescriptionUS Patent 3118022 - Gerhard M. Sessler James E. West - Bell labs - electroacustic transducer - foil electret condenser microphone 1962 1964 - pages 1-3.png
United States patent 3118022 of first foil electret microphone (electroacoustic transducer), invented by G. M. Sessler and J. E. West at Bell Laboratories in 1962.
Source
This file is lacking source information.
Please edit this file's description and provide a source.
https://creativecommons.org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse
Original upload log
The original description page was
here. All following user names refer to en.wikipedia.
2007-08-31 16:55
Nasoeng 3964×1958×1 (211793 bytes) United Staten patent of first electret microphone (electroacustic transducer), invented by G. M. Sessler and J. E. West at Bell Laboratories in 1962.
Information
Captions
Add a one-line explanation of what this file represents
{{Information |Description=United States patent 3118022 of first foil electret microphone (electroacustic transducer), invented by G. M. Sessler and J. E. West at Bell Laboratories in 1962. |Source=Originally from [http://en.wikipedia.org en.wikipedia]; d
File usage
The following pages on the English Wikipedia use this file (pages on other projects are not listed):