Fundamental voice frequency measured by electroglottography during continuous speech. A new exact secondary sex characteristic in boys in puberty

Hearing the physical condition: The relationship between sexually dimorphic vocal traits and underlying physiology

A growing amount of research has shown associations between sexually dimorphic vocal traits and physiological conditions related to reproductive advantage. This paper presented a review of the literature on the relationship between sexually dimorphic vocal traits and sex hormones, body size, and physique. Those physiological conditions are important in reproductive success and mate selection. Regarding sex hormones, there are associations between sex-specific hormones and sexually dimorphic vocal traits; about body size, formant frequencies are more reliable predictors of human body size than pitch/fundamental frequency; with regard to the physique, there is a possible but still controversial association between human voice and strength and combat power, while pitch is more often used as a signal of aggressive intent in conflict. Future research should consider demographic, cross-cultural, cognitive interaction, and emotional motivation influences, in order to more accurately assess the relationship between voice and physiology. Moreover, neurological studies were recommended to gain a deeper understanding of the evolutionary origins and adaptive functions of voice modulation.

Paralinguistic Features Communicated through Voice can Affect Appraisals of Confidence and Evaluative Judgments

This article unpacks the basic mechanisms by which paralinguistic features communicated through the voice can affect evaluative judgments and persuasion. Special emphasis is placed on exploring the rapidly emerging literature on vocal features linked to appraisals of confidence (e.g., vocal pitch, intonation, speech rate, loudness, etc.), and their subsequent impact on information processing and meta-cognitive processes of attitude change. The main goal of this review is to advance understanding of the different psychological processes by which paralinguistic markers of confidence can affect attitude change, specifying the conditions under which they are more likely to operate. In sum, we highlight the importance of considering basic mechanisms of attitude change to predict when and why appraisals of paralinguistic markers of confidence can lead to more or less persuasion.

Perceptual Measures of Boychoir Voices During the Phases of Pubertal Voice Mutation

BACKGROUND/OBJECTIVES

Vocal changes in the male singing voice associated with puberty are variable and often unpredictable resulting in challenges for the singer and the choral director. Limited knowledge regarding the physiologic changes in the vocal mechanism as they correlate to perceptual variations observed in the male adolescent singer exists in the literature. The purpose of this study was to examine pitch breaks and perceptual characteristics of vocal quality during singing tasks for boys in various stages of the male changing voice.

STUDY DESIGN

Prospective Study.

METHODS

Twenty-eight boys were initially evaluated at Cooksey Stage 0 (Pubertal Unchanged; n = 15) or Cooksey Stage 1 (Mid-Voice; n = 13). Range of age was 8-13 years old. Participants performed vocal slide intervals (1-3-1, 1-5-1, 1-8-1) with discrete starting frequencies on G3, C4, F4, and A4 and sang the "Star-Spangled Banner" in the key of Ab. Pitch breaks and perceptual qualities were evaluated on the recorded tasks by expert raters. Seven boys were evaluated again when they progressed to Cooksey Stage 4 (Baritone) performing the same singing tasks.

RESULTS

For the participants evaluated at Cooksey Stage 0/1, pitch breaks were observed more in the higher frequencies and increased interval spacing regardless of starting frequency. Participants at Cooksey Stage 0 had more pitch breaks than Stage 1. At Cooksey Stage 4, an increase in the number of pitch breaks was observed in comparison to their tasks performed at Stage 0/1 and the perceptual quality of breathiness was significantly greater.

CONCLUSIONS

Pitch breaks are a characteristic perceptual change that indicates a young man may be transitioning through puberty. Findings from the present study demonstrate that in addition to perceived pitch breaks, breathiness was noted to significantly increase as the male progressed through puberty. Breathiness was noted to be more significant than vocal timbre and overall vocal quality. This research provides acoustic evidence to enhance the perceptual characteristics of voice change for those who teach and train male voices through puberty.

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.

Does he sound cooperative? Acoustic correlates of cooperativeness

The sound of the voice has several acoustic features that influence the perception of how cooperative the speaker is. It remains unknown, however, whether these acoustic features are associated with actual cooperative behaviour. This issue is crucial to disentangle whether inferences of traits from voices are based on stereotypes, or facilitate the detection of cooperative partners. The latter is likely due to the pleiotropic effect that testosterone has on both cooperative behaviours and acoustic features. In the present study, we quantified the cooperativeness of native French-speaking men in a one-shot public good game. We also measured mean fundamental frequency, pitch variations, roughness, and breathiness from spontaneous speech recordings of the same men and collected saliva samples to measure their testosterone levels. Our results showed that men with lower-pitched voices and greater pitch variations were more cooperative. However, testosterone did not influence cooperative behaviours or acoustic features. Our finding provides the first evidence of the acoustic correlates of cooperative behaviour. When considered in combination with the literature on the detection of cooperativeness from faces, the results imply that assessment of cooperative behaviour would be improved by simultaneous consideration of visual and auditory cues.

Voice break in boys-temporal relations with other pubertal milestones and likely causal effects of BMI

STUDY QUESTION

How is timing of voice break related to other male pubertal milestones as well as to BMI?

SUMMARY ANSWER

We provide a comprehensive temporal analysis of male pubertal milestones, including reproductive hormone dynamics, confirm voice break as a late milestone of male puberty and report a likely causal relationship between higher BMI and earlier age at voice break in men.

WHAT IS KNOWN ALREADY

Voice break represents a late pubertal milestone and recalled age at voice break is frequently used in epidemiological studies as a measure of puberty. In contrast, clinical studies use mainly testicular enlargement and/or genital tanner stage as the marker of pubertal onset. However, neither correlation of pubertal milestones nor reproductive hormone dynamics have been assessed in detail previously. Further, although BMI and puberty timing are known to be closely linked, cause and effect between these traits are not known.

STUDY DESIGN, SIZE, DURATION

The study included a population-based mixed cross-sectional and longitudinal cohort (2006-2014, COPENHAGEN Puberty Study) of 730 healthy Danish boys. Data for 55 871 male research participants from the 23andMe study were obtained, including genome-wide single nucleotide polymorphism data and age at voice break.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We performed a detailed evaluation of pubertal milestones and reproductive hormone levels (study population 1). A Mendelian randomization (MR) approach was used to determine the likely causal link between BMI and timing of voice break (study population 2).

MAIN RESULTS AND THE ROLE OF CHANCE

Voice break occurred at mean age 13.6 (95% CI: 13.5-13.8) years. At voice break, mean (95% CI) testosterone levels, LH levels and bi-testicular volume were 10.9 (10.0-11.7) nmol/L, 2.4 (2.2-2.5) IU/L and 24 (23-25) mL, respectively. Voice break correlated moderately strongly with timing of male pubertal milestones, including testicular enlargement, gonadarche, pubarche, sweat odor, axillary hair growth and testosterone above limit of detection (r2 range: 0.43-0.61). Timing of all milestones was negatively associated with age-specific BMI (all P ≤ 0.001). MR analyses inferred likely causal effects of higher BMI on earlier voice break in males (-0.35 years/approximate SD, P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

Participation rate of the population-based cohort was 25%. Further, boys that were followed longitudinally were examined approximately every 6 months limiting the time resolution of pubertal milestones. Using adult BMI as exposure instead of prepubertal BMI in the MR analysis and the known inaccuracies of the testosterone immunoassay at low testosterone levels may be further limitations.

WIDER IMPLICATIONS OF THE FINDINGS

We provide valuable normative data on the temporal relation of male pubertal milestones. Further, the likely causal relationship between BMI and puberty timing highlights the importance of preventing obesity in childhood.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by Danish Agency for Science, Technology and Innovation (09-067 180); Danish Ministry of the Environment, CeHoS (MST-621-00 065); Capital Region of Denmark (R129-A3966); Ministry of Higher Education and Science (DFF-1331-00 113); Innovation Fund Denmark (InnovationsFonden, 14-2013-4); The International Center for Research and Research Training in Endocrine Disrupting Effects of Male Reproduction and Child Health. B.H., F.R.D., J.R.B.P. and K.K.O. are supported by the Medical Research Council (MC_UU_12015/2). The 23andMe study is supported by the National Human Genome Research Institute of the National Institutes of Health (R44HG006981). Members of the 23andMe Research Team are employees of 23andMe, Inc. and hold stock or stock options in 23andMe.

TRIAL REGISTRATION NUMBER

NCT01411527.

Hadza Men With Lower Voice Pitch Have a Better Hunting Reputation

Previous research with hunter-gatherers has found that women perceive men with voices manipulated to be lower in pitch to be better hunters, and men perceive women with lower pitch to be better gatherers. Here, we test if actual voice pitch is associated with hunting and gathering reputations in men and women, respectively. We find that voice pitch does relate to foraging reputation in men, but not in women, with better hunters having a lower voice pitch. In addition, we find that the previously documented relationship between voice pitch and reproductive success no longer holds when controlling for hunting reputation, but hunting reputation remains a significant predictor of reproductive success when controlling for voice pitch. This raises the possibility that voice pitch is being selected for in hunter-gatherers because of the relationship between voice pitch and hunting reputation.

Voice Mutation During Adolescence in Mangalore, India: Implications for the Assessment and Management of Mutational Voice Disorders

BACKGROUND

The knowledge of vocal mutation is important for speech pathologists in the diagnosis and management of individuals with mutational voice disorders. However, data on vocal mutation in the Indian population are scarce and hence the present study was planned to investigate the age of attainment of vocal mutation in boys and girls from Mangalore, India, in the age range of 8-18 years.

METHODS

A total of 600 participants in the age range of 8-18 years were divided into 10 groups with a 1-year interval. Sustained phonation /a/ and a narration were recorded. Two-way analysis of variance was used to obtain significant difference between the means across age and gender for the fundamental frequency and formant frequency measures.

RESULTS

There was significant main effect of groups for fundamental frequency measure in boys, with post hoc tests revealing statistically significant differences from 14 years of age onward. However, the cutoff criteria of 140 Hz in boys and 240 Hz in girls were attained only by 16 years of age in boys and 15 years in girls, indicating that 16 and 15 years as the ages of onset of vocal mutation in boys and girls, respectively. Results also revealed that first formant frequency undergoes changes from 13 years onward. However, F2 changes from 16 years of age, with no significance observed in F3.

CONCLUSION

The results of the present study are useful in the assessment and management of individuals with mutational voice disorders.

Age- and sex-related variations in vocal-tract morphology and voice acoustics during adolescence

Distinct differences in the human voice emerge during adolescence, with males producing deeper and more resonant voices than females by the end of sexual maturation. Using magnetic resonance images of heads and voice recordings obtained in 532 typically developing adolescents, we investigate what might be the drivers of this change in voice, and the subjective judgment of the voice "maleness" and "femaleness". We show clear sex differences in the morphology of voice-related structures during adolescence, with males displaying strong associations between age (and puberty) and both vocal-fold and vocal-tract length; this was not the case in female adolescents. At the same time, males (compared with females) display stronger associations between age (and puberty) with both fundamental frequency and formant position. In males, vocal morphology was a mediator in the relationship between bioavailable testosterone and acoustic indices. Subjective judgment of the voice sex could be predicted by the morphological and acoustic parameters in males only: the length of vocal folds and its acoustic counterpart, fundamental frequency, is a larger predictor of subjective "maleness" of a voice than vocal-tract length and formant position.

Vocal fundamental and formant frequencies are honest signals of threat potential in peripubertal males

Fundamental and formant frequencies influence perceived pitch and are sexually dimorphic in humans. The information content of these acoustic parameters can illuminate the forces of sexual selection shaping vocal sex differences as well as the mechanisms that ensure signal reliability. We use multiple regression to examine the relationships between somatic (height, adiposity, and strength) and acoustic (fundamental frequency [F₀], formant position [P_f], and fundamental frequency variation [F₀-SD]) characteristics in a sample of peripubertal Bolivian Tsimane. Results indicate that among males-but not females-strength is the strongest predictor of F₀ and P_f and that F₀ and P_f are independent predictors of strength when height and adiposity are controlled. These findings suggest that listeners may attend to vocal frequencies because they signal honest, nonredundant information about male strength and threat potential, which are strongly related to physical maturity and which cannot be ascertained from visual or other indicators of height or adiposity alone.

Androgen receptor mutations are associated with altered epigenomic programming as evidenced by HOXA5 methylation

Male external genital differentiation is accompanied by implementation of a long-term, male-specific gene expression pattern indicating androgen programming in cultured genital fibroblasts. We hypothesized the existence of an epigenetic background contributing to this phenomenon. DNA methylation levels in 2 normal scrotal fibroblast strains from 46,XY males compared to 2 labia majora fibroblast strains from 46,XY females with complete androgen insensitivity syndrome (AIS) due to androgen receptor (AR) mutations were analyzed by Illumina GoldenGate methylation arrays®. Results were validated with pyrosequencing in labia majora fibroblast strains from fifteen 46,XY patients and compared to nine normal male scrotal fibroblast strains. HOXA5 showed a significantly higher methylation level in complete AIS. This finding was confirmed by bisulfite pyrosequencing of 14 CpG positions within the HOXA5 promoter in the same strains. Extension of the 2 groups revealed a constant low HOXA5 methylation pattern in the controls in contrast to a highly variable methylation pattern in the AIS patients. HOXA5 represents a candidate gene of androgen-mediated promoter methylation. The constantly low HOXA5 DNA methylation level of normal male scrotal fibroblast strains and the frequently high methylation levels in labia majora fibroblast strains in AIS indicate for the first time that androgen programming in sexual differentiation is not restricted to global gene transcription but also occurs at the epigenetic level.

Voice pitch alters mate-choice-relevant perception in hunter-gatherers

In humans, voice pitch is thought to be a cue of underlying quality and an important criterion for mate choice, but data from non-Western cultures have not been provided. Here we test attributions to and preferences for voices with raised and lowered pitch in hunter-gatherers. Using a forced-choice playback experiment, we found that both men and women viewed lower pitched voices in the opposite sex as being better at acquiring resources (e.g. hunting and gathering). While men preferred higher pitched women's voices as marriage partners, women showed no overall preference for voice pitch in men. However, women who were currently breastfeeding had stronger preferences for higher pitched male voices whereas women not currently breastfeeding preferred lower pitched voices. As testosterone is considered a costly signal associated with dominance, heritable immunity to infection and low paternal investment, women's preferences potentially reflect a trade-off between securing good genes and paternal investment. Men's preferences for higher pitched female voices are probably due to an evolved preference for markers of fecundity, reflected in voice pitch.

Relationship Between Weight, Speaking Fundamental Frequency, and the Appearance of Phonational Gaps in the Adolescent Male Changing Voice

This 12-month prospective longitudinal study used acoustic analysis to identify phonational gaps in the vocal range of adolescent boys undergoing voice change and to investigate the relationship between the appearance of phonational gaps, weight gain, and changes in speaking fundamental frequency (SF0). Eighteen pubescent boys were recorded producing three descending and three ascending glides over their physiological voice range using the vowel "ah." Recordings were digitized over the range 0-16 kHz and then analyzed to determine both the frequency range and appearance and frequency characteristics of the phonational gaps. Data were plotted against changes in weight and SF0 both as an indicator of pubertal development and to test the hypothesis that changes in weight and SF0 were related to the appearance of phonational gaps. Results indicated that minimum F0 decreased significantly over the time period and phonational gaps increased significantly, but there were no significant changes in maximum F0 or range. Individual data indicated the initial appearance of a lower-frequency gap followed by a higher-frequency gap before the long-term establishment of a midrange gap. At time 5, all boys in the weight range 42.7-44.9 kg had either low- or high-range gaps. The SF0 for this group varied from 117 to 216 Hz. All boys heavier than 54.8 kg had highly variable phonational gaps. SF0 range for this group was 99.5-151 Hz. Transitory low- then high-frequency phonational gaps appeared before the establishment of a midrange phonational gap. In this study, these phonational gaps were associated with certain weight ranges and rapid weight gain, with changes to boys' speaking voices, and with loss of ability to use the mid- and falsetto vocal range.

Stimmleistungsparameter bei Kindern und Jugendlichen

The influence of physical development and singing activity on vocal efficiency in children and adolescents is well known from clinical experience. There is, however, no comparative study between singing and non-singing children which also considers the influence of age and gender. Therefore, standard values for evaluation in clinical practice are missing. We examined the following parameters in 164 healthy children and adolescents (90 boys, 74 girls; 11-16 years), 86 without singing activity (group A) and 78 members of children's and youth choirs (group B): frequency and dynamic range of voice and its borders with a voice range profile, mean fundamental frequency (normal and loud phonation), maximum voice intensity, and maximum duration of intonation. The statistical analysis was performed using three-way ANOVA. We found significantly higher ranges of frequency and intensity in singing children and adolescents (p<0.0001). The borders of the dynamic range and the upper border of the frequency range were significantly higher in group B (p<0.0001). The boys in group B used a higher mean fundamental frequency during loud phonation. There were no significant differences between groups in maximum voice intensity (p=0.051) but a tendency towards higher values in singing children. As an unexpected result, we found significantly higher values in maximum duration of intonation in group A (p<0.0001) independent of age and gender, which seems to be related to the methods used. Regular training of the singing voice results in positive effects on several voice parameters in children as well as adolescents. Our results can be used for estimating standard values in professional clinical and educational care of young singing voices and non-singing children. For this purpose, voice range profile is particularly suitable.

Fundamental Frequency Histograms Measured by Electroglottography During Speech: A Pilot Study for Standardization

This study was designed to develop a database for the electroglottographic measurement of fundamental frequency (Fo) in normal subjects in running speech, for reference in the diagnosis and follow-up of dysphonic patients. A prospective pilot study included 20 healthy male volunteers without laryngeal disorder. Electroglottographic recordings of speaking Fo during connected speech (French) were obtained from two texts with different prosodic content. Fo histograms were sensitive to the variation of speaking Fo between both texts. Graphic representation of the range and distribution of the Fo of the speaker were designed as normalized Fo histograms with plot lines at 5th and 95th percentiles. Less than 5% variability of Fo histograms was recorded when recording more than 15 subjects. This pilot study designed a graphic display of standardized electroglottographic Fo measurements during the physiological condition of connected speech. As the degree of Fo variability depends on the phonetic contents of the text and on the language spoken, a separate histogram for normal subjects needs to be developed in each country or at least for each voice laboratory, with a standard, previously chosen text.

Voice changes after androgen therapy for hypogonadotrophic hypogonadism

OBJECTIVES/HYPOTHESIS

Males with isolated hypogonadotropic hypogonadism (IHH) fail to undergo normal sexual development, including the lack of masculinization of the larynx. The objective of this study was to measure the mean vocal fundamental frequency (MF0) in IHH patients and determine the impact of androgen treatment. An additional aim was to compare the MF0 between IHH patients and controls.

STUDY DESIGN

Prospective observational study.

METHODS

Twenty-four patients with IHH were identified along with 30 normal males and females. Voice recordings were obtained on all subjects. Androgen therapy was administered to the IHH patients. The MF0 and serum sex hormone levels were measured before treatment and at intervals during therapy. These results were compared with the pretreatment data within the IHH group. Voice parameters were also compared between the pre- and posttreatment IHH patients and the normal males and females.

RESULTS

The MF0 in untreated IHH patients was 229 +/- 41 Hz. This was intermediate between the normal male (150 +/- 22 Hz, P < .001) and normal female patients (256 +/- 29 Hz, P < .01). After treatment, the MF0 in the IHH group decreased to 173 +/- 30 Hz (P < .0001); indeed, their posttreatment MF0 approached that of normal males (P < .08). Serum hormone levels responded to the injected testosterone, but these levels did not directly correlate with MF0.

CONCLUSIONS

MF0 in IHH patients is intermediate between normal male and female levels. After treatment with testosterone, these values approach the range of normal males. This prospective study details the impact of androgens on the larynx and vocal function in patients with IHH.

Have women's voices lowered across time? A cross sectional study of Australian women's voices

Various aspects of our communication are well known to have changed over time (1-3). This article describes a cross-sectional study that examined the acoustic characteristics of two groups of Australian women aged 18-25 years from recordings made in 1945 and 1993 and investigated the possible changes in the voice across generations. Archival recordings from 1945 which had been used in a longitudinal study (4) were compared to recordings made in 1993. The results of this study show that women in 1993 have significantly deeper voices than women of the same age recorded in 1945. The possible factors influencing this change are discussed.

Changes in the male voice at puberty

The changes in the male voice in relation to the biological characteristics of puberty were assessed longitudinally in 26 boys. Speaking and singing fundamental frequencies were analysed in relation to the Tanner staging of puberty, saliva testosterone levels, and the Cooksey classification of voice analysis. There were abrupt changes in voice characteristics between Tanner stages G3 and G4 and more gradually from stages C3 to C5 of Cooksey. Although testosterone concentrations were not predictive of the changes, there was a correlation with testis volume. Voice fundamental frequencies were seen to change abruptly in late puberty, in contrast with previous studies. There is a good correlation between the Tanner and Cooksey methods of classification during male puberty.

Motor speech impairment in a case of childhood basilar artery stroke: treatment directions derived from physiological and perceptual assessment

The perceptual and physiological characteristics of the speech of a nine year old child who suffered a basilar artery stroke at the age of five years were investigated using a battery of perceptual and physiological instrumental measures. Perceptual tests administered included the Frenchay Dysarthria Assessment, a perceptual analysis of a speech sample based on a reading of the Grandfather Passage and a phonetic intelligibility test. Instrumental procedures included: spirometric and kinematic analysis of speech breathing; electroglottographic evaluation of laryngeal function, nasometric assessment of velopharyngeal function and evaluation of lip and tongue function using pressure transducers. Physiological assessment indicated the most severe deficits to be in the respiratory and velopharyngeal sub-systems with significant deficits in the articulatory sub-system, all of which resulted in severely reduced intelligibility. These results were compared and contrasted with the subject's performance on the perceptual assessment battery. In a number of instances the physiological assessments were able to identify deficits in the functioning of components of the speech production apparatus either not evidenced by the perceptual assessments or where the findings of the various perceptual assessments were contradictory. The resulting comprehensive profile of the child's dysarthria demonstrated the value of using an assessment battery comprised of both physiological and perceptual methods. In particular, the need to include instrumental analysis of the functioning of the various subcomponents of the speech production apparatus in the assessment battery when defining the treatment priorities for children with acquired dysarthria is highlighted. Treatment priorities determined on the basis of both the perceptual and physiological assessments for the present CVA case are discussed.

Fundamental voice frequency and jitter in girls and boys measured with electroglottography: influence of age and height

The fundamental frequency and jitter of the voice was measured by electroglottography in 71 children between the age of 7 and 15 years. In this series of children the fundamental frequency and jitter did not depend on the gender. The median (range) fundamental frequency was 244 (182-331) Hz in girls and 250 (205-293) Hz in boys. It decreased with increasing height (r = -0.59; P < 0.0005) and age (r = -0.57; P < 0.001). The median jitter ratio was 9.7 (1.6-33.3) in girls and 10.3 (2.0-4.3) in boys. The jitter ratio was negatively related to height (r = -0.31; P < 0.05), but not to age.

Development of aerodynamic aspects in children's voice

To determine the changes with increasing age in children this study measured the air flow and the acoustic signal in children aged 4-15 years. The subglottal pressure was estimated from the intraoral pressure during the phonation of the word 'ipipi'. From these parameters the glottal resistance and the glottal efficiency were calculated. Since these parameters depend on the sound pressure level, a linear regression of the parameters versus the sound pressure level was done, and the values for 75 dB SPL were taken for statistical analysis. The study found a subglottal pressure in younger children between 6 and 10 cm water column, which seemed to diminish with age. The phonatory flow rate was between 50 and 150 ml/s in younger children, which seemed to increase with age. The glottal resistance did not depend on age, values of 20-250 Ns/m5 at a sound pressure level of 75 dB exceed those for adults given in the literature. The measurements for the glottal efficiency showed a broad variability between 20 ppm and 400 ppm.

A longitudinal pilot study on phonetograms/voice profiles in pre-pubertal choir boys

The phonetogram or voice profile, measuring frequency combined with intensity of the voice, has replaced simple measurement of tone ranges for analysis of professional boys choirs. Knowledge of the relationship between pubertal, sex hormones, and phonetogram development has been established in stratified studies. The connection between the singing voice in puberty and other pubertal phenomena needs documentation in longitudinal studies also. Therefore, a pilot study was carried out, where three boys aged 13-15 years were analysed at intervals of 2 months. Measurement of phonetograms, free and total serum testosterone and sex hormone binding globulin (SHBG) showed a significant relationship between SHBG and lowering of the lowest tones in the phonetograms (P < 0.01) confirming earlier stratified studies.

Fundamental voice frequency in female puberty measured with electroglottography during continuous speech as a secondary sex characteristic. A comparison between voice, pubertal stages, oestrogens and androgens

The change of fundamental voice frequency in continuous speech in female puberty was analysed in 47 girls by comparison of 2000 consecutive electroglottographic cycles in a reading situation. The results were compared with serum concentrations of androgens (dihydroepiandrosterone, delta-4-androstenedione, testosterone, and sex hormone binding globulin), oestrogens (oestradiol, oestrone, and oestronesulphate), and somatic puberty (weight, height, mamma stages, and pubic hair stages). Fundamental frequency in continuous speech was related only to oestrone r = -0.34, (P less than 0.05). But the tone range in continuous speech and the lowest tone in the phonetogram were found to be significantly correlated with many of the pubertal and hormone parameters. All these correlations could be explained by a common age-dependency. By multiple regression analysis different sets of variables for prediction of speaking fundamental frequency were found before and after menarche.