Patent · US Expired

Back-masking effect generator

US5509079A · kind A · utility

2Cited by
6References
19Claims
0Family size

Inventor

Key dates

Filing dateSep 13, 1993
Grant dateApr 16, 1996
Priority date
Expiry dateSep 13, 2013

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04K2203/12
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

The present invention is an audio special effect generator which simulates, almost in real time, the sound of an input audio signal being played in reverse. An input audio signal is digitized and read into memory locations in an SRAM which are sequentially addressed from zero until a predetermined address is reached at which point the data stored is read out to an output terminal in reverse order, i.e., the SRAM is addressed from the predetermined address back to zero. For each read, the data read out of the SRAM is replaced with new data from the input audio signal. When the address reaches zero again, the address begins to be incremented again as the data in each location continues to be read out to the output terminal while being replaced by data from the audio input signal. This operation continues until disabled, thus producing an audio output which is a series of audio signal packets which are copies of portions of the input audio signal reproduced in reverse.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.