Browse Prior Art Database

Speech Processing System

IP.com Disclosure Number: IPCOM000094665D
Original Publication Date: 1965-Apr-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Rothauser, E: AUTHOR

Abstract

This vocoder system includes circuitry for controlling the gain of the speech signal for effecting, first, dynamic compression, and then dynamic expansion of the signals in the individual spectrum channels of the system. This enables optimization of certain characteristics of the circuitries in the individual channels.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 2

Speech Processing System

This vocoder system includes circuitry for controlling the gain of the speech signal for effecting, first, dynamic compression, and then dynamic expansion of the signals in the individual spectrum channels of the system. This enables optimization of certain characteristics of the circuitries in the individual channels.

The speech signal to be transmitted is supplied by microphone 10 to preamplifier 12. The latter produces a signal of sufficient magnitude to operate Spectrum Filter Set SFS1, Excitation Function Generator EFG, and an Amplitude Detector AD. SFS1 segregates frequency characteristics of the speech signal into a number of channels C1... CN. Each channel includes a variable amplifier 14-1... 14-N, the gain of which is controlled via a signal on line 16 which is inversely proportional to the output of AD. Thus, the dynamic range of the signals in C1...CN is compressed in a manner which compensates for amplitude changes in the original input signal. The output of EFG is a series of pulses, the power of which is regulated by a Excitation Pulse Regulator EPR, in accordance with a signal on line 18 from AD. The modified excitation signal on line 20 thus includes the loudness information of the original signal at microphone 10. The transmitter signals are fed through time-multiplex transmitter TMX and thence to a time-multiplex receiver TMR. TMR feeds the The transmitter signals are fed through time-multiplex transmitter TMX and thence to a time-multiplex receiver TMR. TMR feeds the informat...