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To investigate the perception of gender from children's voices, adult listeners were presented with /hVd/ syllables, in isolation and in sentence context, produced by children between 5 and 18 years. Half the listeners were informed of the age of the talker during trials, while the other half were not. Correct gender identifications increased with talker age; however, performance was above chance even for age groups where the cues most often associated with gender differentiation (i.e., average fundamental frequency and formant frequencies) were not consistently different between boys and girls. The results of acoustic models suggest that cues were used in an age-dependent manner, whether listeners were explicitly told the age of the talker or not. Overall, results are consistent with the hypothesis that talker age and gender are estimated jointly in the process of speech perception. Furthermore, results show that the gender of individual talkers can be identified accurately well before reliable anatomical differences arise in the vocal tracts of females and males. In general, results support the notion that the transmission of gender information from voice depends substantially on gender-dependent patterns of articulation, rather than following deterministically from anatomical differences between male and female talkers.

Listeners show better-than-chance discrimination of nasalized and oral vowels occurring in appropriate consonantal contexts. Yet, the methods for investigating partial perceptual compensation for nasal coarticulation often include nasal and oral vowels containing naturally different pitch contours. Listeners may therefore be discriminating between these vowels based on pitch differences and not nasalization. The current study investigates the effect of pitch variation on the discrimination of nasalized and oral vowels in C_N and C_C items. The f0 contour of vowels within paired discrimination trials was varied. The results indicate that pitch variation does not influence patterns of partial perceptual compensation for coarticulation.

Researchers investigating the vowel systems of languages or dialects frequently employ normalization methods to minimize between-speaker variability in formant patterns while preserving between-phoneme separation and (socio-)dialectal variation. Here two methods are considered: log-mean and Lobanov normalization. Although both of these methods express formants in a speaker-dependent space, the methods differ in their complexity and in their implied models of human vowel-perception. Typical implementations of these methods rely on balanced data across speakers so that researchers may have to reduce the data available in the analyses in missing-data situations. Here, an alternative method is proposed for the normalization of vowels using the log-mean method in a linear-regression framework. The performance of the traditional approaches to log-mean and Lobanov normalization against the regression approach to the log-mean method using naturalistic, simulated vowel-data was investigated. The results indicate that the Lobanov method likely removes legitimate linguistic variation from vowel data and often provides very noisy estimates of the actual vowel quality associated with individual tokens. The authors further argue that the Lobanov method is too complex to represent a plausible model of human vowel perception, and so is unlikely to provide results that reflect the true perceptual organization of linguistic data.

Adult listeners were presented with /hVd/ syllables spoken by boys and girls ranging from 5 to 18 years of age. Half of the listeners were informed of the sex of the speaker; the other half were not. Results indicate that veridical age in children can be predicted accurately based on the acoustic characteristics of the talker's voice and that listener behavior is highly predictable on the basis of speech acoustics. Furthermore, listeners appear to incorporate assumptions about talker sex into their estimates of talker age, even when information about the talker's sex is not explicitly provided for them.

Apparent-talker height is determined by a talker's fundamental frequency (f0) and spectral information, typically indexed using formant frequencies (FFs). Barreda [(2017b). J. Acoust. Soc. Am. 141, 4781-4792] reports that the apparent height of a talker can be influenced by vowel-specific variation in the f0 or FFs of a sound. In this experiment, native speakers of Mandarin were presented with a series of syllables produced by talkers of different apparent heights. Results indicate that there is substantial variability in the estimated height of a single talker based on lexical tone, as well as the inherent f0 and FFs of vowel phonemes.

The perception of apparent-talker height is mostly determined by the fundamental frequency (f0) and spectral characteristics of a voice. Although it is traditionally thought that spectral cues affect apparent-talker height by influencing apparent vocal-tract length, a recent experiment [Barreda (2016). J. Phon. 55, 1-18] suggests that apparent-talker height can vary significantly within-talker on the basis of phonemically-determined spectral variability. In this experiment, listeners were asked to estimate the height of 10 female talkers based on manipulated natural productions of bVd words containing one of /i æ ɑ u ɝ/. Results indicate that although listeners appear to use vocal-tract length estimates in determining apparent-height, apparent-talker height also varies significantly within-talker based on the inherent spectral and source characteristics of different vowels, with vowels with lower formant-frequencies and f0 being associated with taller talkers overall. The use of spectral and f0 information in apparent-height estimation varied considerably between listeners, resulting in additional variation in the apparent-height of talkers. Although the use of acoustic information in the determination of apparent-height was highly systematic, it does not necessarily follow from the empirical relationship between speech acoustics and actual talker height.

The vocal tract length of a speaker is the primary determinant of the range of formant frequencies (FFs) produced by that speaker. Listeners have demonstrated sensitivity to the average FFs produced by voices, for example, in estimating the relative heights of two speakers based on their speech. However, it is not known whether they can learn to identify voices based on the acoustic characteristic associated with the average FFs produced by a voice (this characteristic will be referred to as FF-scaling). To investigate this, a series of vowels corresponding to voices that differed in their average f0 and/or FF-scaling were synthesized. Listeners (n = 71) were trained to identify these voices using a training procedure where, for each trial, they heard the vowels representing a voice and then had to identify the stimulus voice from among a series of candidate voices that differed in terms of their FF-scaling and/or their f0. Results indicate that listeners can identify voices on the basis of FF-scaling quite accurately and consistently after only a short training session and that, although f0 weakly influences these estimates, they are most strongly determined by the stimulus FFs.

Many experiments have reported a perceptual advantage for vowels presented in blocked-versus mixed-voice conditions. Nusbaum and colleagues [Nusbaum and Morin (1992). in Speech Perception, Speech Production, and Linguistic Structure, edited by Y. Tohkura, Y. Sagisaka, and E. Vatikiotis-Bateson (OHM, Tokyo), pp. 113-134; Magnuson and Nusbaum (2007). J. Exp. Psychol. Hum. Percept. Perform. 33(2), 391-409] present results which suggest that the size of this advantage may be related to the facility with which listeners can detect speaker changes, so that combinations of less similar voices can result in better performance than combinations of more similar voices. To test this, a series of synthetic voices (differing in their source characteristics and/or formant-spaces) was used in a speeded-monitoring task. Vowels were presented in blocks made up of tokens from one or two synthetic voices. Results indicate that formant-space differences, in the absence of source differences between voices in a block, were unlikely to result in the perception of multiple voices, leading to lower accuracy and relatively faster reaction times. Source differences between voices in a block resulted in the perception of multiple voices, increased reaction times, and a decreased negative effect of formant-space differences between voices on identification accuracy. These results are consistent with a process in which the detection of speaker changes guides the appropriate or inappropriate use of extrinsic information in normalization.

Several experiments have found that changing the intrinsic f0 of a vowel can have an effect on perceived vowel quality. It has been suggested that these shifts may occur because f0 is involved in the specification of vowel quality in the same way as the formant frequencies. Another possibility is that f0 affects vowel quality indirectly, by changing a listener's assumptions about characteristics of a speaker who is likely to have uttered the vowel. In the experiment outlined here, participants were asked to listen to vowels differing in terms of f0 and their formant frequencies and report vowel quality and the apparent speaker's gender and size on a trial-by-trial basis. The results presented here suggest that f0 affects vowel quality mainly indirectly via its effects on the apparent-speaker characteristics; however, f0 may also have some residual direct effects on vowel quality. Furthermore, the formant frequencies were also found to have significant indirect effects on vowel quality by way of their strong influence on the apparent speaker., (© 2012 Acoustical Society of America.)