Improving Speech Communication in High Noise Environments

During speech the vocal folds vibrate resulting in audible sounds that are transmitted through the vocal tract as well as vibrations that are transmitted through the body tissue to the skin surface. These skin surface vibrations can be detected by contact microphones and used to transmit speech. However, the skin attenuates high frequency content and in some locations muffles the signal resulting in poor speech quality. To reconstruct a signal that better matches the microphone signal a finite impulse response filter is fit to an average transfer function of the accelerometer signal. When implemented this filter restores much of the lost frequency content and in the presence of background noise results in a signal with good intelligibility and less noise than the microphone signal