Compressed air gramophone
One of the earliest versions was the Auxetophone, designed by the British engineer Sir Charles Parsons. It was capable of producing sufficient volume to broadcast public music performances from the top of the Blackpool Tower, and was said to be loud enough to cause people to vacate the front rows of seats in an auditorium.
A pneumatic amplifier was realised by using a sensitive valve, which required little force to operate, to modulate the flow of a stream of compressed air. The basic principle of the valves used in these devices was to pass the stream of compressed air through two partially overlapping combs. The sound vibrations to be amplified were applied to one of the combs, causing it to move laterally in relation to the other comb, varying the degree of overlap and so altering the flow of compressed air in sympathy with the sound vibrations.
- Reiss, Eric (2007). The compleat talking machine: a collector's guide to antique phonographs. Chandler, Ariz: Sonoran Pub. p. 217. ISBN 1886606226.
- Pi. "More Defunct Technology: The Auxetophone". PSU ASA: The Penn State Chapter of the Acoustical Society of America. Retrieved 2012-07-31.
- "1906 Victor Auxetophone". Montana Phonograph Company. Retrieved 2012-07-31.
- http://www.douglas-self.com/MUSEUM/COMMS/auxetophone/auxetoph.htm "The Auxetophone & Other Compressed-Air Gramophones" Retrieved 19th June 2012
- Wierzbicki (2009), p. 74; "Representative Kinematograph Shows" (1907).The Auxetophone and Other Compressed-Air Gramophones explains pneumatic amplification and includes several detailed photographs of Gaumont's Elgéphone, which was apparently a slightly later and more elaborate version of the Chronomégaphone.
- "Lexikon der Filmbegriffe: Auxetophon". Christian-Albrechts-Universität zu Kiel. 02.03.2012. Retrieved 2012-07-31. (in German)
|This sound technology article is a stub. You can help Wikipedia by expanding it.|