Control of voice gender in pre-pubertal children

The Effect of Fundamental Frequency on Gender Perception in Prepubertal Children: Insights from the LoKiS Database

This study examines the impact of fundamental frequency on gender perception in prepubertal children in the LoKiS database - a longitudinal project collecting and analyzing recordings of approximately 60 German primary school children aged 6 to 10years. Spontaneous and content-controlled audio recordings were collected in two German primary schools. Three distinct listening experiments with over 100 listeners were conducted. In the first experiment, listeners judged the gender of the voices on a seven-point scale. The second experiment explored the relationships between perceptual attribute ratings and corresponding acoustic parameters associated with fundamental frequency. The third experiment utilized voice morphing techniques to investigate the influence of fundamental frequency on gender perception while controlling for other acoustic parameters. About one-third of the children receive unambiguous gender attributions. The perceived gender difference between children assigned female at birth (AFAB) and assigned male at birth (AMAB) increases from first to third grade. The feminine-sounding children were perceived as significantly higher-pitched and more melodious. A strong correlation between perceived pitch and measured fundamental frequency was found. While the acoustic analysis revealed only a few significant differences between AFAB and AMAB children in general, the feminine-sounding children exhibited markedly higher values than the masculine-sounding ones. Stronger differences of fundamental frequency and semitone range occur as AFAB and AMAB children get older. Linear mixed models confirm a significant influence of fundamental frequency and semitone range on gender perception. Other interacting factors include the speech material used, as well as the gender of the listener. The influence of fundamental frequency was even more pronounced when controlling for other acoustic parameters.

Human talkers change their voices to elicit specific trait percepts

The voice is a variable and dynamic social tool with functional relevance for self-presentation, for example, during a job interview or courtship. Talkers adjust their voices flexibly to their situational or social environment. Here, we investigated how effectively intentional voice modulations can evoke trait impressions in listeners (Experiment 1), whether these trait impressions are recognizable (Experiment 2), and whether they meaningfully influence social interactions (Experiment 3). We recorded 40 healthy adult speakers' whilst speaking neutrally and whilst producing vocal expressions of six social traits (e.g., likeability, confidence). Multivariate ratings of 40 listeners showed that vocal modulations amplified specific trait percepts (Experiments 1 and 2), which could be explained by two principal components relating to perceived affiliation and competence. Moreover, vocal modulations increased the likelihood of listeners choosing the voice to be suitable for corresponding social goals (i.e., a confident rather than likeable voice to negotiate a promotion, Experiment 3). These results indicate that talkers modulate their voice along a common trait space for social navigation. Moreover, beyond reactive voice changes, vocal behaviour can be strategically used by talkers to communicate subtle information about themselves to listeners. These findings advance our understanding of non-verbal vocal behaviour for social communication.

The Acoustic and Perceptual Correlates of Gender in Children's Voices

PURPOSE

This study investigates the perceptual and acoustic correlates of gender in prepubertal voices. The study is part of a longitudinal project analyzing recordings of circa 60 German primary school children from the first to fourth grades (6- to 10-year-olds).

METHOD

Spontaneous and content-controlled audio recordings were made of 62 first-grade children (29 girls, 33 boys; age: 6- to 7-year-olds) from two German primary schools. Information on gender conformity was also recorded. A total of 167 listeners judged the gender of the voices on a 7-point scale. The results of the listening experiments and gender conformity ratings were related to a range of typical acoustic parameters.

RESULTS

Measures of self-reported gender conformity differ significantly between the boys and the girls. Sixteen of the 62 children show unambiguous gender attributions in the listening experiment. A hierarchical cluster analysis including gender perception, gender conformity, and acoustic parameters shows four different types of speakers. Two multiple regression models revealed a significant main effect of fundamental frequency on the gender perception ratings of the listening experiment across and within gender. Significant correlations were found between the center of gravity and skewness of the sibilants and gender conformity, especially for the male speakers.

CONCLUSIONS

Fundamental frequency plays an important role in influencing perceptual judgments, whereas sibilant spectra are correlated with gender conformity. In further listening experiments, we will examine in more detail the role of individual acoustic parameters and analyze how the vocal expression of gender and gender conformity in individual children develops before reaching puberty.

Effect of Anchor Term on Auditory-Perceptual Ratings of Feminine and Masculine Speakers

BACKGROUND

Studies investigating auditory perception of gender expression vary greatly in the specific terms applied to gender expression in rating scales.

PURPOSE

This study examined the effects of different anchor terms on listeners' auditory perceptions of gender expression in phonated and whispered speech. Additionally, token and speaker cues were examined to identify predictors of the auditory-perceptual ratings.

METHOD

Inexperienced listeners (n = 105) completed an online rating study in which they were asked to use one of five visual analog scales (VASs) to rate cis men, cis women, and transfeminine speakers in both phonated and whispered speech. The VASs varied by anchor term (very female/very male, feminine/masculine, feminine female/masculine male, very feminine/not at all feminine, and not at all masculine/very masculine).

RESULTS

Linear mixed-effects models revealed significant two-way interactions of gender expression by anchor term and gender expression by condition. In general, the feminine female/masculine male scale resulted in the most extreme ratings (closest to the end points), and the feminine/masculine scale resulted in the most central ratings. As expected, for all speakers, whispered speech was rated more centrally than phonated speech. Additionally, ratings of phonated speech were predicted by mean fundamental frequency (f _o) within each speaker group and by smoothed cepstral peak prominence in cisgender speakers. In contrast, ratings of whispered speech, which lacks an f _o, were predicted by indicators of vocal tract resonance (second formant and speaker height).

CONCLUSIONS

The current results indicate that differences in the terms applied to rating scales limit generalization of results across studies. Identifying the patterns across listener ratings of gender expression provide a rationale for researchers and clinicians when making choices about terms. Additionally, beyond f _o and vocal tract resonance, predictors of listener ratings vary based on the anchor terms used to describe gender expression.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19617564.

Individual Differences in the Development of Gendered Speech in Preschool Children: Evidence From a Longitudinal Study

PURPOSE

We evaluated whether naive listeners' ratings of the gender typicality of the speech of children assigned male at birth (AMAB) and children assigned female at birth (AFAB) were different at two time points: one at which children were 2.5-3.5 years old and one when they were 4.5-5.5 years old. We also examined whether measures of speech, language, and inhibitory control predicted developmental changes in these ratings.

METHOD

A group of adults (N = 80) rated single-word productions of 55 AMAB and 55 AFAB children on a continuous scale from "definitely a boy" to "definitely a girl." Children's productions were taken from previous longitudinal study of phonological development and vocabulary growth. As part of that study, children completed a battery of standardized and nonstandardized tests at both time points.

RESULTS

Listener ratings for AMAB and AFAB children were significantly different at both time points. The difference was larger at the later time point, and this was due entirely to changes in the ratings of AMAB children's speech. A measure of language production and a measure of inhibitory control predicted developmental changes in these ratings, albeit only weakly, and not in a consistent direction.

CONCLUSIONS

The gender typicality of AMAB and AFAB children's speech is perceptibly different for children as young as 2.5 years old. Developmental changes in perceived gender typicality are driven by changes in the speech of AMAB children. The learning of gendered speech is not constrained or facilitated by overall speech and language skill.

Peer audience effects on children's vocal masculinity and femininity

Existing evidence suggests that children from around the age of 8 years strategically alter their public image in accordance with known values and preferences of peers, through the self-descriptive information they convey. However, an important but neglected aspect of this 'self-presentation' is the medium through which such information is communicated: the voice itself. The present study explored peer audience effects on children's vocal productions. Fifty-six children (26 females, aged 8-10 years) were presented with vignettes where a fictional child, matched to the participant's age and sex, is trying to make friends with a group of same-sex peers with stereotypically masculine or feminine interests (rugby and ballet, respectively). Participants were asked to impersonate the child in that situation and, as the child, to read out loud masculine, feminine and gender-neutral self-descriptive statements to these hypothetical audiences. They also had to decide which of those self-descriptive statements would be most helpful for making friends. In line with previous research, boys and girls preferentially selected masculine or feminine self-descriptive statements depending on the audience interests. Crucially, acoustic analyses of fundamental frequency and formant frequency spacing revealed that children also spontaneously altered their vocal productions: they feminized their voices when speaking to members of the ballet club, while they masculinized their voices when speaking to members of the rugby club. Both sexes also feminized their voices when uttering feminine sentences, compared to when uttering masculine and gender-neutral sentences. Implications for the hitherto neglected role of acoustic qualities of children's vocal behaviour in peer interactions are discussed. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part II)'.

Singers show enhanced performance and neural representation of vocal imitation

Humans have a remarkable capacity to finely control the muscles of the larynx, via distinct patterns of cortical topography and innervation that may underpin our sophisticated vocal capabilities compared with non-human primates. Here, we investigated the behavioural and neural correlates of laryngeal control, and their relationship to vocal expertise, using an imitation task that required adjustments of larynx musculature during speech. Highly trained human singers and non-singer control participants modulated voice pitch and vocal tract length (VTL) to mimic auditory speech targets, while undergoing real-time anatomical scans of the vocal tract and functional scans of brain activity. Multivariate analyses of speech acoustics, larynx movements and brain activation data were used to quantify vocal modulation behaviour and to search for neural representations of the two modulated vocal parameters during the preparation and execution of speech. We found that singers showed more accurate task-relevant modulations of speech pitch and VTL (i.e. larynx height, as measured with vocal tract MRI) during speech imitation; this was accompanied by stronger representation of VTL within a region of the right somatosensory cortex. Our findings suggest a common neural basis for enhanced vocal control in speech and song. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.

Vocomotor and Social Brain Networks Work Together to Express Social Traits in Voices

Voice modulation is important when navigating social interactions-tone of voice in a business negotiation is very different from that used to comfort an upset child. While voluntary vocal behavior relies on a cortical vocomotor network, social voice modulation may require additional social cognitive processing. Using functional magnetic resonance imaging, we investigated the neural basis for social vocal control and whether it involves an interplay of vocal control and social processing networks. Twenty-four healthy adult participants modulated their voice to express social traits along the dimensions of the social trait space (affiliation and competence) or to express body size (control for vocal flexibility). Naïve listener ratings showed that vocal modulations were effective in evoking social trait ratings along the two primary dimensions of the social trait space. Whereas basic vocal modulation engaged the vocomotor network, social voice modulation specifically engaged social processing regions including the medial prefrontal cortex, superior temporal sulcus, and precuneus. Moreover, these regions showed task-relevant modulations in functional connectivity to the left inferior frontal gyrus, a core vocomotor control network area. These findings highlight the impact of the integration of vocal motor control and social information processing for socially meaningful voice modulation.

What Acoustic Studies Tell Us About Vowels in Developing and Disordered Speech

Purpose Literature was reviewed on the development of vowels in children's speech and on vowel disorders in children and adults, with an emphasis on studies using acoustic methods. Method Searches were conducted with PubMed/MEDLINE, Google Scholar, CINAHL, HighWire Press, and legacy sources in retrieved articles. The primary search items included, but were not limited to, vowels, vowel development, vowel disorders, vowel formants, vowel therapy, vowel inherent spectral change, speech rhythm, and prosody. Results/Discussion The main conclusions reached in this review are that vowels are (a) important to speech intelligibility; (b) intrinsically dynamic; (c) refined in both perceptual and productive aspects beyond the age typically given for their phonetic mastery; (d) produced to compensate for articulatory and auditory perturbations; (e) influenced by language and dialect even in early childhood; (f) affected by a variety of speech, language, and hearing disorders in children and adults; (g) inadequately assessed by standardized articulation tests; and (h) characterized by at least three factors-articulatory configuration, extrinsic and intrinsic regulation of duration, and role in speech rhythm and prosody. Also discussed are stages in typical vowel ontogeny, acoustic characterization of rhotic vowels, a sensory-motor perspective on vowel production, and implications for clinical assessment of vowels.

"This Is What a Mechanic Sounds Like": Children's Vocal Control Reveals Implicit Occupational Stereotypes

In this study, we explored the use of variation in sex-related cues of the voice to investigate implicit occupational stereotyping in children. Eighty-two children between the ages of 5 and 10 years took part in an imitation task in which they were provided with descriptions of nine occupations (three traditionally male, three traditionally female, and three gender-neutral professions) and asked to give voices to them (e.g., “How would a mechanic say . . . ?”). Overall, children adapted their voices to conform to gender-stereotyped expectations by masculinizing (lowering voice pitch and resonance) and feminizing (raising voice pitch and resonance) their voices for the traditionally male and female occupations, respectively. The magnitude of these shifts increased with age, particularly in boys, and was not mediated by children’s explicit stereotyping of the same occupations. We conclude by proposing a simple tool based on voice pitch for assessing levels of implicit occupational-gender stereotyping in children.

Physiological and perceptual correlates of masculinity in children's voices

Low frequency components (i.e. a low pitch (F0) and low formant spacing (ΔF)) signal high salivary testosterone and height in adult male voices and are associated with high masculinity attributions by unfamiliar listeners (in both men and women). However, the relation between the physiological, acoustic and perceptual dimensions of speakers' masculinity prior to puberty remains unknown. In this study, 110 pre-pubertal children (58 girls), aged 3 to 10, were recorded as they described a cartoon picture. 315 adults (182 women) rated children's perceived masculinity from the voice only after listening to the speakers' audio recordings. On the basis of their voices alone, boys who had higher salivary testosterone levels were rated as more masculine and the relation between testosterone and perceived masculinity was partially mediated by F0. The voices of taller boys were also rated as more masculine, but the relation between height and perceived masculinity was not mediated by the considered acoustic parameters, indicating that acoustic cues other than F0 and ΔF may signal stature. Both boys and girls who had lower F0, were also rated as more masculine, while ΔF did not affect ratings. These findings highlight the interdependence of physiological, acoustic and perceptual dimensions, and suggest that inter-individual variation in male voices, particularly F0, may advertise hormonal masculinity from a very early age.

Corner vowels in males and females ages 4 to 20 years: Fundamental and F1-F4 formant frequencies

The purpose of this study was to determine the developmental trajectory of the four corner vowels' fundamental frequency (f_o) and the first four formant frequencies (F1-F4), and to assess when speaker-sex differences emerge. Five words per vowel, two of which were produced twice, were analyzed for f_o and estimates of the first four formants frequencies from 190 (97 female, 93 male) typically developing speakers ages 4-20 years old. Findings revealed developmental trajectories with decreasing values of f_o and formant frequencies. Sex differences in f_o emerged at age 7. The decrease of f_o was larger in males than females with a marked drop during puberty. Sex differences in formant frequencies appeared at the earliest age under study and varied with vowel and formant. Generally, the higher formants (F3-F4) were sensitive to sex differences. Inter- and intra-speaker variability declined with age but had somewhat different patterns, likely reflective of maturing motor control that interacts with the changing anatomy. This study reports a source of developmental normative data on f_o and the first four formants in both sexes. The different developmental patterns in the first four formants and vowel-formant interactions in sex differences likely point to anatomic factors, although speech-learning phenomena cannot be discounted.

Children can control the expression of masculinity and femininity through the voice

Pre-pubertal boys and girls speak with acoustically different voices despite the absence of a clear anatomical dimorphism in the vocal apparatus, suggesting that a strong component of the expression of gender through the voice is behavioural. Initial evidence for this hypothesis was found in a previous study showing that children can alter their voice to sound like a boy or like a girl. However, whether they can spontaneously modulate these voice components within their own gender in order to vary the expression of their masculinity and femininity remained to be investigated. Here, seventy-two English-speaking children aged 6-10 were asked to give voice to child characters varying in masculine and feminine stereotypicality to investigate whether primary school children spontaneously adjust their sex-related cues in the voice-fundamental frequency (F0) and formant spacing (ΔF)-along gender stereotypical lines. Boys and girls masculinized their voice, by lowering F0 and ΔF, when impersonating stereotypically masculine child characters of the same sex. Girls and older boys also feminized their voice, by raising their F0 and ΔF, when impersonating stereotypically feminine same-sex child characters. These findings reveal that children have some knowledge of the sexually dimorphic acoustic cues underlying the expression of gender, and are capable of controlling them to modulate gender-related attributes, paving the way for the use of the voice as an implicit, objective measure of the development of gender stereotypes and behaviour.

The role of sex-related voice variation in children's gender-role stereotype attributions

In the absence of clear sex differences in vocal anatomy, the expression of gender in pre-pubertal children's voices has a strong behavioural dimension. However, whether children are sensitive to this gender-related variation in the voice and use it to make inferences about their peers' masculinity and femininity remains unexplored. Using a cross-modal matching task, thirty-one 7- to 8-year-olds and forty-two adults were asked to associate prototypical voices of boys and girls, and their re-synthesized masculinized and feminized versions, to fictional stereotypically masculine, gender-neutral, and stereotypically feminine child characters. We found that listeners spontaneously associated stereotypically masculine and feminine descriptors of a child character with masculinized voices and feminized voices, respectively. Adults made overall more stereotypical associations and were less influenced by character sex than children. Our observations highlight for the first time the contribution of acoustic cues to gender stereotyping from childhood, and its potential implications for the gender schema literature. Statement of contribution What is already known on this subject? Research on stereotyping shows children's schematic processing of the visible aspects of gender expression Psychoacoustic research shows that variation in children's voices affects adults' judgments of their masculinity What does this study add? Children and adults linked voice variation to gender-stereotypical characterizations of child characters Adults made overall more stereotypical associations than children and were less influenced by character's sex Our results highlight the existence of a vocal component in children's and adults' gender schemas.

Vocal characteristics of 5-year-old children: proposed normative values based on a French-speaking population†

Purpose: Previous research proposed normative data on gender- and age-specific voice acoustics for adults. Such reference values are lacking for children, particularly under the age of 6. This study was intended (1) to collect reliable normative data for the acoustic parameters of 5-year-old children's voices, and (2) to investigate potential gender-specific differences.Study: Prospective and cross-sectional.Methods: Acoustic analyses were done on the voices of 53 normophonic children (26 girls; 27 boys) aged 5;0-5;11 years, using Praat software. The fundamental frequency, local jitter, local shimmer, and noise-to-harmonics ratio (NHR) were measured on the sustained vowels [a], [i], and [u]. The highest frequency, lowest frequency, and frequency range were measured using ascending and descending glissandi on the vowel [a].Results: For the three sustained vowels, the mean fundamental frequency ranged from 255 Hz to 277 Hz, mean jitter ranged from 0.394% to 0.591%, mean shimmer ranged from 2.571% to 5.824%, and mean NHR ranged from 0.009 to 0.034. The frequency range was from 190 Hz to 750 Hz, which corresponds to 23.7 semitones. No gender difference was found, except for NHR on the vowel [a].Conclusions: The lack of gender differences - other than for NHR on the vowel [a] - led us to propose mixed norms for 5-year-old boys and girls combined.Implications: These normative data will allow clinicians to compare children's voice assessments to specific references in order to enhance diagnostic accuracy and measure therapy outcomes.

Static measurements of vowel formant frequencies and bandwidths: A review

PURPOSE

Data on vowel formants have been derived primarily from static measures representing an assumed steady state. This review summarizes data on formant frequencies and bandwidths for American English and also addresses (a) sources of variability (focusing on speech sample and time sampling point), and (b) methods of data reduction such as vowel area and dispersion.

METHOD

Searches were conducted with CINAHL, Google Scholar, MEDLINE/PubMed, SCOPUS, and other online sources including legacy articles and references. The primary search items were vowels, vowel space area, vowel dispersion, formants, formant frequency, and formant bandwidth.

RESULTS

Data on formant frequencies and bandwidths are available for both sexes over the lifespan, but considerable variability in results across studies affects even features of the basic vowel quadrilateral. Origins of variability likely include differences in speech sample and time sampling point. The data reveal the emergence of sex differences by 4 years of age, maturational reductions in formant bandwidth, and decreased formant frequencies with advancing age in some persons. It appears that a combination of methods of data reduction provide for optimal data interpretation.

CONCLUSION

The lifespan database on vowel formants shows considerable variability within specific age-sex groups, pointing to the need for standardized procedures.

Seven and up: individual differences in male voice fundamental frequency emerge before puberty and remain stable throughout adulthood

Voice pitch (the perceptual correlate of fundamental frequency, F0) varies considerably even among individuals of the same sex and age, communicating a host of socially and evolutionarily relevant information. However, due to the almost exclusive utilization of cross-sectional designs in previous studies, it remains unknown whether these individual differences in voice pitch emerge before, during or after sexual maturation, and whether voice pitch remains stable into adulthood. Here, we measured the F0 parameters of men who were recorded once every 7 years from age 7 to 56 as they participated in the British television documentary Up Series. Linear mixed models revealed significant effects of age on all F0 parameters, wherein F0 mean, minimum, maximum and the standard deviation of F0 showed sharp pubertal decreases between age 7 and 21, yet remained remarkably stable after age 28. Critically, men's pre-pubertal F0 at age 7 strongly predicted their F0 at every subsequent adult age, explaining up to 64% of the variance in post-pubertal F0. This finding suggests that between-individual differences in voice pitch that are known to play an important role in men's reproductive success are in fact largely determined by age 7, and may therefore be linked to prenatal and/or pre-pubertal androgen exposure.

Volitional exaggeration of body size through fundamental and formant frequency modulation in humans

Several mammalian species scale their voice fundamental frequency (F0) and formant frequencies in competitive and mating contexts, reducing vocal tract and laryngeal allometry thereby exaggerating apparent body size. Although humans’ rare capacity to volitionally modulate these same frequencies is thought to subserve articulated speech, the potential function of voice frequency modulation in human nonverbal communication remains largely unexplored. Here, the voices of 167 men and women from Canada, Cuba, and Poland were recorded in a baseline condition and while volitionally imitating a physically small and large body size. Modulation of F0, formant spacing (∆F), and apparent vocal tract length (VTL) were measured using Praat. Our results indicate that men and women spontaneously and systemically increased VTL and decreased F0 to imitate a large body size, and reduced VTL and increased F0 to imitate small size. These voice modulations did not differ substantially across cultures, indicating potentially universal sound-size correspondences or anatomical and biomechanical constraints on voice modulation. In each culture, men generally modulated their voices (particularly formants) more than did women. This latter finding could help to explain sexual dimorphism in F0 and formants that is currently unaccounted for by sexual dimorphism in human vocal anatomy and body size.

Fundamental Frequency of Crying in Two-month-old Boys and Girls: Do Sex Hormones During Mini-puberty Mediate Differences?

OBJECTIVE

To evaluate whether the puberty-like sex hormone surge during the first months of life (mini-puberty) affects fundamental frequency (fo) in infant crying as one would derive from hormone influences on voice in adults.

STUDY DESIGN

Populational prospective study.

PARTICIPANTS

Twenty healthy normal-hearing infants (nine boys) were recruited for participation.

METHODS

Spontaneously uttered cries were collected from each infant at 8 weeks of age. The cries were acoustically analyzed for mean fo and fo range. The fo properties were correlated to the average serum levels of bioavailable estradiol (E2) (mean E2/sex hormone-binding globulin [SHBG]) and testosterone (T) (mean T/SHBG) across the second month of life.

RESULTS

Whereas no significant hormone effect was found for mean fo, a significant negative correlation (r = -0.55) was found between fo range and mean E2/SHBG. No indication for a T influence on fo features was found at this age. Although girls showed a slightly higher mean E2 concentration than boys did, the observed differences in cry fo range were judged to be reflective of an infant's serum concentration of E2 rather than a sex-based difference.

CONCLUSION

In the absence of laryngeal size differences between female and male infants, the result was interpreted as indicative of an E2 influence on viscoelastic properties of the vocal folds. In our opinion, the investigation of young infants' vocalizations during the early postnatal surge of sex steroids (mini-puberty) may advance our understanding of the mechanisms mediating average sex differences in vocal development and early communication.

Reliable acoustic measurements in children between 5;0 and 9;11 years: Gender, age, height and weight effects on fundamental frequency, jitter and shimmer in phonations without and with controlled voice SPL

BACKGROUND

Current pediatric voice assessment guidelines include instrumental measurements of fundamental frequency (F0) and the perturbation indices jitter and shimmer. In children below 10 years, gender, age, height and weight effects on these parameters have been inconsistently characterized. Recent research in healthy children showed, that differences in habitual speaking voice intensity (voice SPL) under the usual assessment procedure significantly affect jitter and shimmer. These effects were reduced in phonations with controlled voice SPL >80dBA. Reliable measurement methods and description of physiologic influencing factors are essential to identify pathologic voices.

OBJECTIVE

This cross-sectional single cohort study investigates in children between 5;0 and 9;11 years how gender, age, height and weight affect voice F0, jitter and shimmer in phonations at individually "medium" voice intensity (modeling the usual clinical practice) and with controlled voice SPL >80dBA.

SUBJECTS AND METHODS

68 vocally healthy children (39 f/29 m) aged 5;0-9;11 years provided 3 prolonged phonations of/a/at individually "medium" and controlled voice intensity at ">80dBA" (visual feedback, 10cm distance). F0 (Hz), jitter (%), shimmer (%) and voice SPL (dBA) were determined with PRAAT. Gender, age, height and weight effects without and with controlled voice SPL were assessed by descriptive statistics, Analysis of Variance and Linear Mixed Models.

RESULTS

F0 (Hz), jitter (%), shimmer (%) and voice SPL (dBA) were significantly different in medium voice compared to >80dBA (p<0.01). In medium phonations girls had a higher F0 than boys (girls: 276.7(50.7), boys: 261.5(33.7)), but with >80dBA this difference was only minimal (girls: 328.9(52.2), boys 327.9(51.2)). Mean jitter (0.27(0.10)) and shimmer (4.34(1.68)) were smaller and showed less spread (jitter: 0.5(0.26); shimmer: 9.47(3.47)) with >80dBA. Gender, age, height and weight had no significant effects on F0, jitter, shimmer and voice SPL in both phonation types (p-range=0.42-0.99).

CONCLUSIONS

Neither without nor with controlled voice SPL there were systematic gender, age, height or weight effects on voice F0, jitter and shimmer. Gender related F0 discrepancies were equalized in phonations with >80dBA. In children below 10 years gender related acoustic voice differences may be mainly linked to behavior, which should be considered in future works regarding physiologic voice development.