Digital Signal Processing Algorithm for Microphone Input Energy Detection Having Adaptive Sensitivity
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
In many audio applications, such as voice recording or speech recognition, a microphone is used as an input device for voice signals. Often, it is desired that the application ignore all microphone input except that which is truly speech. The determination of whether the input is speech or noise is often achieved by comparing the input signal amplitude to a predetermined value, known as the noise threshold. If the input amplitude is above this threshold, it is determined that the input is speech. Otherwise, it is determined that the input is background noise and the input is ignored. This determination method, while simple and inexpensive to implement, has a serious drawback in that the background noise level may not be equal to the predetermined threshold.