Precise Time Resolution Research Articles

More Visible Speech

This paper presents a method for visual display of acoustical waveforms with which different phonemes are more readily distinguished than with spectrograms. The visual display is based on the interval between successive up crossings of the zero axis in the waveform. Although zero crossings and tip crossings have been used by several investigators since Licklinder's studies demonstrating that zero-crossing information is sufficient for intelligibility of speech, most investigators have ignored an essential property of up-crossing analysis. Analysis of up crossings is a time domain technique and as such, allows a perfect resolution of events in time, a resolution which is lost if the up-crossing data is averaged over intervals of time. Such precise time resolution is critical for the recognition of certain distinguishing features in various consonants. These features permit a visual display in which the phonemes can easily be distinguished, even in connected speech. Furthermore, the important features for discriminating among the consonants are highly speaker invariant.