Perceptual Search for Frequency-Spectral Boundary
Sadanand Singh, Abraham Tishman · The Journal of the Acoustical Society of America · 1968
The problem in phoneme perception is to discover what acoustic parameters of speech stimuli and what portions of a given parameter are used as perceptual cues. A phoneme and phoneme class can be located on a two- or multidimensional space. In this experiment, phoneme boundaries were located on the frequency-spectral plane of the voiceless fricatives of English. Five 20-yr-old native English speakers, whose audiograms were normal, listened to each of six syllables in approximately 700 predetermined bands of frequencies ranging from 37.5 to 9600 Hz. The subject herself controlled the bandpass-filter knobs (60 dB/oct rolloff), varying the properties of stimuli to which she was listening. This method, suggested by Chistovich, is quite useful when it is necessary to present to subjects large set of stimuli. Also, the responses of different subjects may conveniently be maintained “because the position of the boundary may be different.” In the results for each stimulus consonant, the frequency-spectral location of voiceless plosives and fricatives were shown as determined by the auditory responses. There were some overlaps between their boundaries and the boundaries of different subjects.