A Study on Alternative Speech Sensor

This paper presents a study on alternative speech sensor for speech processing applications. Noise robustness is one of the major considerations in speech processing systems. In presence of noise, speech signal renders unintelligible naturally and thus degrades the performance of automatic speech recognition systems. Close-talk microphone perfums well for clean speech signals. The close-talk microphone based recognition performance fails under real non-stationary conditions and also degraded strongly by the background noise. One way of improving such a system performance is by the use of alternative sensors, which are attached to the speaker's skin and receive the uttered speech through throat or bones. There are two types of sensors namely alternative acoustic and non-acoustic sensors. First, alternative acoustic sensors are more isolated from environmental noise and pick up the speech signal in a robust manner. Second is to develop noisy robust speech recognition system using Multi-sensor approach. This approach combines the information from different sources of acoustic speech sensors. The thirdinvolves non-acoustic speech sensors, which are primarily used for speaker identification task and some speech recognition applications. Fourth, discusses the speech enhancement methods for the noisy speech signal. These approaches help to improve the speech recognition system in noisy conditions and lead to building a robust ASR system.