Categorization in the Perception of Breathy Voice Quality and Its Relation to Voice Production in Healthy Speakers

Abstract

Purpose Previous studies of speech articulation have shown that individuals who can perceive smaller differences between similar-sounding phonemes showed larger contrasts in their productions of those phonemes. Here, a similar relationship was examined between the perception and production of breathy voice quality. Method Twenty females with healthy voices were recruited to participate in both a voice production and a perception experiment. Each participant produced repetitions of a sustained vowel, and acoustic correlates of breathiness were calculated. Identification and discrimination tasks were performed with a series of synthetic stimuli along a breathiness continuum. Categorical boundary location and boundary width were obtained from the identification task as a measurement of perception of breathiness. Spearman's correlation analysis was performed to estimate associations between values of boundary location and width and the acoustic correlates of breathiness from the participants' voices. Results Significant correlations between boundary width (r = -.53 to -.6) and some acoustic correlates were found, but no significant relationships were observed between boundary location and the acoustic correlates. Conclusions Speakers with small boundary widths, which suggest higher perceptual precision in differentiating breathiness, had typical voices that were less breathy, as estimated with acoustic measures, compared to speakers with large boundary widths. Our findings may support a link between perception and production of breathy voice quality. Supplemental Material https://doi.org/10.23641/asha.9808478.

Figure 1.

Schematic of study hypotheses on the effects of boundary location (A) and boundary widths (B) on auditory targets. Acoustic space represents actual acoustic distances of the stimuli represented as white circles on the breathiness continuum. Perceptual space represents how listeners would perceive the stimuli, and shorter distances between stimuli would represent more perceptual similarity. The color green indicates stimuli that would be perceived as typical voices; purple indicates stimuli that would be perceived as breathy voices. Auditory targets represent acoustic regions that the listeners would target when they produce their typical or breathy voices.

Figure 2.

Scatter plots and best linear fits of boundary location versus smoothed cepstral peak prominence (CPPS), harmonics-to-noise ratio (HNR), and high-to-low spectral ratio (HL ratio). Spearman's correlations are represented as r values. No significant correlations were found between boundary location and the acoustic measures.

Figure 3.

Scatter plots and best linear fits of boundary width versus smoothed cepstral peak prominence (CPPS), harmonics-to-noise ratio (HNR), and high-to-low spectral ratio (HL ratio). Spearman's correlations are represented as r values. *p < .05.

Figure 4.

Mean smoothed cepstral peak prominence (CPPS), harmonics-to-noise ratio (HNR), and high-to-low spectral ratio (HL ratio) of each group. Error bars indicate 95% confidence intervals. *Speakers with narrow boundaries had significantly higher CPPS and HNR than speakers with wide boundaries.

Figure 5.

(Left) A scatter plot and a best linear fit of boundary width versus breathiness rating from the Consensus Auditory–Perceptual Evaluation of Voice with Spearman's correlation represented as an r value. (Right) Mean breathiness ratings of each group. Error bars indicate 95% confidence intervals. *Speakers with narrow boundaries had significantly lower breathiness ratings than speakers with wide boundaries.

Figure 6.

Identification curves for all participants, divided into narrow and wide boundary groups (n = 10 each). The x-axes represent the stimuli number. The y-axes are omitted. Each curve starts with 0 identification percentage at Stimuli 1 and ends with 100 identification percentage at Stimuli 10.

Figure 7.

Boundary discrimination and averaged nonboundary discrimination percentages of individual participants (red: narrow boundary group, blue: wide boundary group), connected by lines.