Manipulation of Consonants in Natural Speech

Natural speech often contains conflicting cues that are characteristic of confusable sounds. For example, the /k/, defined by a mid-frequency burst within 1-2 kHz, may also contain a high-frequency burst above 4 kHz indicative of /ta/, or vice versa. Conflicting cues can cause people to confuse the two sounds in a noisy environment. An efficient way of reducing confusion and improving speech intelligibility in noise is to modify these speech cues. This paper describes a method to manipulate consonant sounds in natural speech, based on our a priori knowledge of perceptual cues of consonants. We demonstrate that: 1) the percept of consonants in natural speech can be controlled through the manipulation of perceptual cues; 2) speech sounds can be made much more robust to noise by removing the conflicting cue and enhancing the target cue.