Speech processing in a high ambient noise environment

Classical communication theory considers preprocessing of speech for more efficient transmission through a noisy channel. However, when a high ambient noise environment is present prior to modulation, conventional techniques break down. This paper discusses speech processing in a high ambient noise environment and how the intelligibility can be improved by using a discrete, adaptive filter whose parameters vary with the form of the speech signal. The intelligibility gain of processed speech over unprocessed speech ranges from 50 percent at very high noise levels to negligible gain at moderate noise levels.