ly, the left ear will detect melodies better than the right ear. Speech is more readily decoded in the left hemisphere than in the right cerebral hemisphere. This is evident in people with brain lesions. The left hemisphere plays a primary role in speech perception (Moore, 1997). Speech ModeSpeech mode is the perception of the restructured phonemes. If phonemes are encoded syllabically, they must be recovered in perception by a suitable decoder. Liberman (1996) stated that perception of phonemes that have been encoded may be expected to differ from the perception of the phonemes that have not been encoded and from non-speech. For example, the transition cues for /d/ in /di/ and /du/ sound like whistles when taken out of speech context. They do not sound like speech or like each other. This example could include transition cues from many other phonemes. With simplified speech of this kind, the listener’s perception is greatly dependent upon whether the listener is in speech mode. It has been found that stimuli with spectral and temporal properties similar to those of speech are learned more readily than stimuli that is simplified, provided that the speech-like stimuli is identified as speech by the listener. Processes different from those underlying the perception of other sounds characterize speech mode. It is strengthened by recent findings that speech and non-speech sounds are processed primarily in different cerebral hemispheres of the brain (Liberman, 1996). According to Moore (1997), speech mode is unusual in that it operates for an entire class of highly complex and varied acoustic signals, whose main feature is that a human vocal tract produced them.Cue TradingSeveral cues may signal a single phonetic contrast. Therefore, it is possible to demonstrate that when the perceptual utility of one cue is attenuated, another cue may take on principal effectiveness in signaling the contrast under scrutiny because both ...
