Perceptual and acoustic gender differences in the speech of 4 1/2 - 5 1/2 year old children.

The linguistic factors which identify a speaker as being either male or female are reasonably well understood and documented when we are considering adult speakers. Many of these factors become apparent at puberty when the sexes diverge along predictable anatomical and physiological paths. It might be expected, therefore, that prepubertal children should appear relatively undifferentiated in terms of gender and that young boys' and girls' speech should be sexually homogenous. This study has confirmed, however, that adult listeners can correctly identify the sex of a prepubertal child from samples of speech. Results of the present study yielded correct identification rates which varied between 66% (using isolated vowels as the sample) and 76% (using sentences as the sample) - all of these rates were significantly greater than chance. Girls were shown to be better identified by listeners than boys and female listeners tended to be more accurate at identifying gender than male listeners. During the acoustic phase of the study, a number of parameters were selected for measurement which were regarded as likely to be involved in the gender-identification process. Overall, there was a surprisingly large number of negative results, with only a very few parameters yielding significantly sex-different outcomes. No differences were found in Fo between the sexes and only 5 out of 18 comparisons of formant frequency showed significant differences. An investigation into vocal breathiness indicated that, on the basis of this parameter, children could be assigned into perceptual groupings ('most / least male-like') better than into biological sex groupings ('boy / girl'). The conclusion reached is that listeners may use different acoustic cues to identify children's sex from speech than adult's sex, alternatively or additionally, they may be able to focus their perceptive skills more finely on the small acoustic inequalities that exist. The concept of gender-specific speech is discussed in a general commentary of the various influences exerted in the formation of gendered-identities

A comparison of two methods of formant frequency estimation for high-pitched voices

This study sought to test the accuracy of two methods of formant frequency estimation: artificial laryngeal stimulation via neck placement and via oral tube insertion. Twenty males between the ages of 18 and 45 performed the following three tasks: (1) four seconds of sustained vowel, (2) two seconds of sustained vowel followed by two seconds of artificial laryngeal stimulation via neck placement while ceasing vocal fold vibration and holding structures of the vocal fold filter in a fixed position, and (3) four seconds of sustained vowel, the last two of which were accompanied by artificial laryngeal stimulation via an oral insertion. These tasks were performed on the vowels/a/ and /i/. Four formant frequencies were measured for each task at second one and second three. These measures were compared across second one and second three, as well as across all three tasks. Group means as well as individual subject analysis were compared

Newborns' preference for female voices as a function of spectral composition

Research with human fetuses and neonates has demonstrated that last trimester fetuses can hear in utero and that neonates prefer auditory stimuli which are experienced prenatally to novel auditory stimuli. This study was conducted to determine if prenatal experience with the lower frequencies of the maternal voice influence postnatal voice preferences. Tape recordings of maternal voices were low-pass filtered at 1000 Hz in order to simulate intrauterine recordings of maternal voices. Neonates were placed in a discriminated-operant choice task in which they could choose between a recording of the maternal unfiltered voice and the maternal low-pass voice. A second group of neonates was presented the same recordings to assess neonates' preferences for low-pass (nonmaternal) female voices in general. The same unfiltered voice recordings were high-pass filtered at 1000 Hz and the high-pass and unfiltered versions of these voices were presented to a third group of neonates to assess their preferences. The high-pass voices were different from any voices experienced while the unfiltered voices were more similar to maternal prenatal voices

Expression and perception of gender in prepubertal children's voice : an acoustic study

The present study described the fundamental frequency (f0) and the first two formant frequencies (F1 and F2) obtained from voice samples produced by 25 male and 26 female Cantonese-speaking prepubertal children under natural (neutral) condition and upon request to mimic the opposite gender voice (imitation condition), to investigate sexual dimorphism in prepubertal children’s voice and to assess their implicit knowledge on voice gender. Average accuracy of voice gender identification by adult listeners was 81.7% and 41.1% for prepubertal children’s voice gender produced under neutral and imitation conditions respectively. No significant difference in f0 was found between genders under neutral condition, suggesting similar vocal mechanism for prepubertal boys and girls. Average F1 and F2 associated with boys were lower than that with girls. It was suggested that both difference in vocal tract length, and the sex-specific articulatory behaviors contributed to the differences in formant frequencies, thus enhancing sexual dimorphism for gender voice identification. Under imitation condition, boys exhibited significantly higher f0 than girls. F1 associated with boys was also higher than that with girls. It could be concluded that prepubertal children had the implicit knowledge on the sexually dimorphic acoustic correlates (f0 and F1) and were capable in altering the vibration rate of vocal folds and the effective vocal tract length upon request to conform to vocal characteristics of the opposite gender.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Acoustical study of the development of stop consonants in children

Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2005.Includes bibliographical references (p. 142-146).This study focuses on the acoustic patterns of stop consonants and adjacent vowels as they develop in young children (ages 2;6-3;3) over a six month period. Speech is generated using a series of articulatory, laryngeal, and respiratory gestures that children must learn to reproduce. As a child's speech develops, the gestures become more precise and coordinated, and the resulting acoustic patterns are refined. To explore their development, over forty different acoustic measurements were made on each of 1049 recorded utterances from ten children, including durational, amplitude, spectral, formant, and harmonic measurements. These acoustic data are interpreted in terms of the supraglottal, laryngeal, and respiratory actions that give rise to them. Data show that some details of the child's gestures are still far from achieving the adult pattern. Children have acquired appropriate positioning of their primary articulator for producing a stop consonant, but are still learning to adjust the tongue body during the consonant production. At constriction release, children have a high incidence of multiple bursts and a short burst duration, interpreted as a reflection of increased articulator compliance, smaller articulator size, and high subglottal pressure. Children are also still acquiring correct adjustment of vocal fold stiffness and glottal spreading as well as intraoral pressure, as evidenced by long voice onset times and highly variable fundamental frequencies. Additionally, amplitude changes over the course of the utterance and high amplitude variability reveal that children have not yet gained full control over subglottal pressure.(cont.) Overall, results indicate that children are less consistent than adults in controlling and coordinating various gestures and with finding the ideal respiration and vocal tract postures, including the stiffness of their articulators. Certain aspects of child speech are found to become more similar to adult values over the six month period of the study.by Annika Karin Karlsson Imbrie.Ph.D