Multidimensional analysis of male and female voices

Abstract

This paper is a sequel to a study which showed that the dominant dimension for perceptual discrimination among normal voices was the male-female categorization and which also suggested that discrimination within the male-female categories utilized distinct dimenisons. The present study eliminates the male-female axis by treating the gender groups separately and making the within-category dimensions available for more sensitive analysis. The purpose was to determine the number and nature of perceptual parameters needed to explain judgments of voice similarity depending on talker sex and whether the stimulus sample was a sustained vowel or a short phrase. The similarity judgments were submitted to multidimensional analysis via INDSCAL and the resulting dimenisons were interpreted in terms of available acoustic measures and unidimensional voice-quality ratings of pitch, breathiness, hoarseness, nasality, and effort. The decisions of the listerners appeared to be influenced by both the sex of the speaker and the stimulus sample, although fundamental frequency (fo), was important for all judgments. Aside from the fo dimensions, judgments concerning male voices were related to vocal tract parameters, while similarity judgments of female voices were related to perceived glottal/vocal tranct differences. Formant structure was apparently important in judging the similarity of vowels for both sexes while perceptual glottal/temporal attributes may have been used as cues in the judgments of phrases.

Speech perception by budgerigars(Melopsittacus undulatus): The voiced-voiceless distinction

“…understanding human perception of complex sounds, such as speech and music, in which the physical correlates of the perceptual experience are often unclear (see, e.g., Murry & Singh, 1980;Shepard, 1980). The present experiment demonstrates that MDS techniques are also useful for studying the perception of complex speech sounds by animals.…”

Speech perception by budgerigars (Melopsittacus undulatus): Spoken vowels

“…The formant frequencies of the natural vowels used in these experiments-particularly FO and F 1-fall well outside the range of best auditory sensitivity and frequency resolving power for budgerigars. Nevertheless, budgerigars do discriminate among these natural speech sounds, and they appear to rely on the same information that humans do in discriminating among vowels (i.e., the relation between F1 and F2 formant frequencies) and among talkers (i.e., FOand F3 formant frequencies) (Murry & Singh, 1980;Singh & Murry, 1978).…”

“…Stimuli with similar perceptual properties are near each other in multidimensional space, whereas stimuli with different perceptual properties are far apart. MDS has proved to be a useful tool for investigating vowel perception in humans (Fox, 1983(Fox, , 1985Murry & Singh, 1980;Singh & Murry, 1978). In the following experiments, budgerigars were tested on natural spoken vowels from five different phonetic categories produced by different talkers.…”

The perceptual structure of pathologic voice quality

“…Further, the small number of voices studied has limited the number of dimensions that may be extracted from a set of data, so that half or more of the variance in the underlying ratings may remain unexplained ͑Murry et Nieboer et al, 1988͒. Other sampling restrictions further limit the generalizability of previous studies. Many published reports have used normal voices ͑e.g., Matsumoto et al, 1973;Walden et al, 1978;Murry and Singh, 1980;Gelfer, 1993͒, but pathologic voices have been studied very little. Many studies that did examine pathologic voices included only a single disordered population ͓e.g., tracheoesophageal speakers ͑Nieboer et al., 1988͒, hoarse voices ͑Isshiki andTakeuchi, 1970; an exception is Hammarberg et al, 1980͔ or focused on specific aspects of voice quality ͑Kreiman et al, 1994͒.…”