Measures Of Fundamental Frequency Research Articles

Different measures of fundamental frequency and vocal satisfaction among transgender men and women.

To verify possible correlations between fo and voice satisfaction among Brazilian transgender people. An observational, cross-sectional quantitative study was conducted with the Trans Woman Voice Questionnaire (TWVQ), voice recording (sustained vowel and automatic speech) and extraction of seven acoustic measurements related to fo position and variability in transgender people. Participants were divided into two groups according to gender. After descriptive and inferential analysis, comparison between both groups was performed by Student's t-test and the correlation between fo measurements and the TWVQ protocol was calculated by Pearson's correlation (p<0.05). A total of 11 transgender women (mean age = 26.91) and seven transgender men (mean age = 26.57) participated in the study. Women desired a slightly feminine voice, scoring 72.8 on the TWVQ, with mean pitch values of 165.2Hz on vowels and 144.5Hz in speech. Men desired a slightly masculine voice, scoring 68.4 on the TWVQ, with mean pitch values of 143.3Hz on vowels and 138.9Hz in speech. Of the seven evaluated measures, only the maximum pitch during number counting by women showed a moderate negative correlation with the TWVQ (p=0.043). Only maximum fo during number counting by transgender women showed a negative correlation with the TWVQ score. Results suggest that although fo may play a role in gender perception by voice, it is not the only determinant of vocal satisfaction in this population.

Investigating the acoustic fidelity of vowels across remote recording methods

Abstract Our study tests the acoustic fidelity of remote recordings, using a large variety of stimuli and recording environments. Remote recordings support crucial uses like reaching isolated populations and more speakers; however, it is important to be aware of any limitations therein. A 188-word list was constructed from each English consonant followed by each vowel. Words recorded by one male and one female speaker in a sound-attenuated booth were input for test recordings. Stimuli were played over an electronic speaker and recorded on six devices across five operating systems, four teleconferencing platforms, and two browsers, using internal and external microphones, a more extensive set than has been analyzed in prior research. Acoustic analysis investigates the impact of these recording configurations on fundamental frequency, loudness, and vowel formant measures. Across recording conditions, browser choice had less effect on the different vowel measures, while choice of hardware resulted in a greater number of significant differences and greater variability within and across conditions. Recording configuration effects were observed to exert different impacts across vowels and speakers, resulting in inconsistent perturbations. These results highlight the need for careful selection and detailed documentation of all recording configurations.

Intelligent measurement of fundamental frequency of complex periodic signals based on maximum periodicity

Intelligent measurement of fundamental frequency of complex periodic signals based on maximum periodicity

Predictive Modeling and Early Detection of Parkinson's Disease Using Machine Learning

Parkinson's disease is a progressive neurodegenerative disorder that impacts millions of citizens in the USA, mainly targeting the motor system and causing debilitating symptoms such as rigidity, tremors, and bradykinesia. The diagnosis of Parkinson's disease is presently heavily dependent on clinical evaluations and neurological examinations, targeting the detection of motor dysfunction. The principal aim of this study was to use machine learning as a means for early detection and prediction of Parkinson's disease. The dataset utilized for this study was the Parkinson’s Disease Dataset, retrieved from the UCI Machine Learning Repository, which included comprehensive biomedical voice measurements from a cohort of individuals, 23 of whom are diagnosed with Parkinson’s disease and 8 who are healthy controls. This dataset included a set of features extracted from voice recordings. These include parameters like fundamental frequency (pitch), amplitude variation, jitter, shimmer, and several phonation-related measures known to reflect early vocal impairments associated with the disease in question. This research project deployed three credible and proven algorithms, namely, logistic regression, random forest, and the Support Vector Machines. Besides, this study employed a combination of metrics, including accuracy, precision, recall, F1-score, and ROC-AUC, which are more holistic toward the model performance. According to the metric performance results of the three models, several key insights were drawn into the early detection of Parkinson's Disease. Particularly, it was clear that the Random Forest model had superior accuracy and was the most reliable in classifying positive cases and healthy patients, which could be that this model turned out to be most reliable in an early detection setting. In that respect, predictive modeling in Parkinson's Disease is a capability frontier that has the potential to make much difference in clinical decision-making. Supported by Machine Learning algorithms, clinicians can trace the minute patterns in patient data, which are not easily visible through any other diagnostic means. In such cases, early detection of Parkinson's Disorder with vocal biomarkers or motor assessment may afford healthcare professionals opportunities for early interventions that might retard the disease process.

The Design and Validation of a High-Precision Angular Vibration Calibration System Based on a Laser Vibrometer.

This paper presents the design and validation of a high-precision angular vibration calibration system based on a laser vibrometer, aimed at meeting the high-precision requirements for measuring small angular vibrations. The system primarily consists of a self-driving angular vibration platform and a laser vibrometer. The platform is isolated from ground interference via an air-floating platform and uses a split-type motor to control the platform, generating specific angular vibrations. Detailed simulations of the platform's modal characteristics and the stability of the spring plates were conducted using the finite element analysis software ANSYS 11. Moreover, fundamental frequency testing and measurement accuracy testing were conducted on the system. Experimental results demonstrate that the system has a fundamental frequency of 2.69 Hz and a maximum measurement error of 0.00172″, confirming the system's effectiveness in dynamic characteristics, stability, and measurement accuracy. This research provides essential technical support for high-precision angular vibration control in spacecraft.

The Effects of Sleep Inertia on the Acoustic and Perceptual Voice Changes in Adult University Students

Background: Sleep inertia, characterized by reduced alertness and cognitive functioning upon waking, has been well-researched in its effects on cognitive and motor abilities. However, its impact on voice quality remains less clear. Objectives: This study aimed to investigate the relationship between sleep inertia following nocturnal sleep and changes in acoustic and perceptual voice parameters in adults. Methods: Ninety healthy participants (45 females, 45 males, ages: 18 - 30 years) took part in a pre-post study using convenience sampling. Their voices were recorded before and after nocturnal sleep across multiple tasks, including vowel /a/ phonation, spontaneous speech, text reading, and maximum phonation time (MPT). Recordings were made in a quiet room using a Zoom H6 recorder at a 44.1 kHz rate. The acoustic analysis included measures of fundamental frequency (F0), standard deviation of F0 (SD F0), vocal intensity, harmonics-to-noise ratio (HNR), cepstral peak prominence smoothed (CPPS), jitter, shimmer, and formant frequencies. Auditory-perceptual evaluation was conducted using the GRBAS Scale. Statistical analysis was performed using SPSS-19. The Shapiro-Wilk test assessed normality, and a paired t-test compared variables, separately for males and females at a 0.05 significance level. Results: Acoustic analysis revealed that both females and males experienced a decrease in mean F0, mean intensity, HNR, and CPPS, and an increase in jitter, shimmer, and SD F0 across most voice samples after sleeping. These changes were particularly significant for females in all voice samples (P &lt; 0.001). Perceptual analysis also showed a significant increase in grade, roughness, breathiness, asthenia, and strain for both genders after sleep (P &lt; 0.001). Conclusions: This study demonstrated that sleep inertia negatively impacts vocal performance, resulting in a decline in voice quality for both genders after sleep compared to before. Notably, this decline in voice quality was more pronounced in women than in men.

Validity of Acoustic Measures Obtained Using Various Recording Methods Including Smartphones With and Without Headset Microphones.

The goal of this study was to assess various recording methods, including combinations of high- versus low-cost microphones, recording interfaces, and smartphones in terms of their ability to produce commonly used time- and spectral-based voice measurements. Twenty-four vowel samples representing a diversity of voice quality deviations and severities from a wide age range of male and female speakers were played via a head-and-thorax model and recorded using a high-cost, research standard GRAS 40AF (GRAS Sound & Vibration) microphone and amplification system. Additional recordings were made using various combinations of headset microphones (AKG C555 L [AKG Acoustics GmbH], Shure SM35-XLR [Shure Incorporated], AVID AE-36 [AVID Products, Inc.]) and audio interfaces (Focusrite Scarlett 2i2 [Focusrite Audio Engineering Ltd.] and PC, Focusrite and smartphone, smartphone via a TRRS adapter), as well as smartphones direct (Apple iPhone 13 Pro, Google Pixel 6) using their built-in microphones. The effect of background noise from four different room conditions was also evaluated. Vowel samples were analyzed for measures of fundamental frequency, perturbation, cepstral peak prominence, and spectral tilt (low vs. high spectral ratio). Results show that a wide variety of recording methods, including smartphones with and without a low-cost headset microphone, can effectively track the wide range of acoustic characteristics in a diverse set of typical and disordered voice samples. Although significant differences in acoustic measures of voice may be observed, the presence of extremely strong correlations (rs > .90) with the recording standard implies a strong linear relationship between the results of different methods that may be used to predict and adjust any observed differences in measurement results. Because handheld smartphone distance and positioning may be highly variable when used in actual clinical recording situations, smartphone + a low-cost headset microphone is recommended as an affordable recording method that controls mouth-to-microphone distance and positioning and allows both hands to be available for manipulation of the smartphone device.

Signal injection techniques for fault location in distribution networks

Over the last 50 years, fault location in transmission systems has been a subject of interest to utility engineers and researchers. Nevertheless, it has not been until the last decades that fault location in distribution networks has started to gain prominence. Traditionally, fault location techniques for distribution networks have been classified in three different groups: fundamental frequency measurements, high frequency measurements and the use of artificial intelligence (AI). Yet despite this rigid classification, a new approach has started to be developed over the last years based on the injection of a discernible signal into the distribution systems, mainly in non-effectively grounded networks. However, even when recent developments of new grounding systems reinforce the possibility of using this kind of techniques, these are not usually cited by general reviews and overviews of fault location systems in distribution networks. Accordingly, this paper aims to provide a general but clear overview on the existing techniques for fault location in distribution networks based on signal injection. Apart from describing the different options presented to date, the most important aspects that characterize them and the injected signal are briefly outlined, as well as a comparative performance analysis.

Influence of vowels on note pitching in a cappella vocal quartet performance

This study aimed to investigate the relationship between the fundamental frequencies employed when singing different vowels on the same pitch for each member in turn of a professional soprano, alto, tenor, bass (SATB) a cappella vocal quartet in terms of the measured fundamental frequency during the production of a set of individual vowels within a four-part carrier phrase. This is an experimental singing production study on the tuning of vowels in the context of a cappella quartet singing. To facilitate this, one singer at a time in a professional a cappella vocal quartet changed the vowel they are singing on a single note concurrent with a consonant a cappella triad being sustained by the other three singers singing a fixed vowel. The first few bars of the a cappella anthem "If ye love me" by Thomas Tallis provided a carrier phrase that ended with a held chord on the chord on the word "me" by three singers against which the remaining singer produced a set of different vowels on their note of the chord. This is carried out for each of the four singers. The hypothesis being investigated is to remain accurately in-tune; fundamental frequency should be varied depending on the vowel being sung. Fundamental frequencies were measured using electrolaryngographs to ensure that there was no acoustic interference that could affect the accuracy of the fundamental frequency measurements if they were obtained from the audio output. The results provide clear evidence of changes being made to the fundamental frequencies of different vowels in an a cappella quartet context, and these changes confirm variations found elsewhere relating to the perceived pitches of different vowels. Measurable and consistent fundamental frequency variations occur when one part tunes different vowels against a reference chord sung by the other three singers in a choral quartet context on a fixed vowel. This has a direct consequence for tuning in a cappella choral music. The importance of carefully tuning individual notes for different vowels in a cappella choral singing requires focused listening to the pitches of the sounds being produced by the other singers in the choir. Usually, all parts are singing common vowels where it is important that the vowels are matched by being carefully blended together and tuning is aimed at being beat-free in just intonation. When compositions require parts to sing different vowels, both intrinsic (production related) and auditory (hearing related) pitch variations become relevant and challenge beat-free tuning.

Acoustic analysis of normal voice patterns in North Indian population

To evaluate the characteristics of voice of the north Indian Hindi speakers across the adult population based on acoustic measures of fundamental frequency (F0), jitter, shimmer, and harmonic-to-noise ratio and to observe the gender differences in these measures. A total of 62 (39 men and 23 women) voice samples from healthy normal voiced adults aged 18-40years were included. Mean fundamental frequency in males and females in the age group 18-25 is 156 and 262, respectively. Similarly mean fundamental frequency in males and females in the age group 26-40 is 141 and 253, respectively. Shimmer in the women (18-25) group and jitter in the men (26-40) group is not normally distributed. Rest all parameters were normally distributed across all groups. Fundamental frequency showed statistically significant gender differences in both the age groups. Jitter and shimmer variables were statistically significant when compared between the two genders in the age group 26-40. Harmonic-to-noise ratio showed a statistically significant difference in the age group 18-25 among both genders. There exists statistically significant negative correlation between smoothed cepstral peak prominence and fundamental frequency, Pearson's r -0.479 (P-value <0.001). All acoustic parameters except intensity show a significant gender difference; however, the participants across each gender revealed no difference in acoustic parameters when segregated into age groups.

Impact of orthognathic surgery on voice and speech: a systematic review and meta-analysis.

Orthognathic surgical procedures, whether in one or both jaws, can affect structures regarding the articulation and resonance of voice and speech. Evaluating the impact of orthognathic surgery on voice and speech performance in individuals with skeletal dentofacial disharmony. Word combinations and truncations were adapted for the following electronic databases: EMBASE, PubMed/Medline, Scopus, Web of Science, Cochrane Library, and Latin American and Caribbean Literature in Health Sciences (LILACS), and grey literature. The research included studies on nonsyndromic adults with skeletal dentofacial disharmony undergoing orthognathic surgery. These studies assessed patients before and after surgery or compared them with individuals with good facial harmony using voice and speech parameters through validated protocols. Two independent reviewers performed all stages of the review. The Joanna Briggs Institute tool was used to assess risk of bias in the cohort studies, and ROBINS-I was used for nonrandomized clinical trials. The authors also performed a meta-analysis of random effects. A total of 1163 articles were retrieved after the last search, of which 23 were read in full. Of these, four were excluded, totalling 19 articles for quantitative synthesis. When comparing the pre- and postoperative periods, both for fundamental frequency, formants, and jitter and shimmer perturbation measures, orthognathic surgery did not affect vowel production. According to the articles, the main articulatory errors associated with skeletal dentofacial disharmonies prior to surgery were distortions of fricative sounds, mainly/s/ and/z/. Orthognathic surgery may have little or no impact on vocal characteristics during vowel production. However, due to the confounding factors involved, estimates are inconclusive. The most prevalent articulatory disorders in the preoperative period were distortion of the fricative phonemes/s/ and/z/. However, further studies must be carried out to ensure greater robustness to these findings. PROSPERO (CRD42022291113).

Voice analytics in the wild: Validity and predictive accuracy of common audio-recording devices.

The use of voice recordings in both research and industry practice has increased dramatically in recent years-from diagnosing a COVID-19 infection based on patients' self-recorded voice samples to predicting customer emotions during a service center call. Crowdsourced audio data collection in participants' natural environment using their own recording device has opened up new avenues for researchers and practitioners to conduct research at scale across a broad range of disciplines. The current research examines whether fundamental properties of the human voice are reliably and validly captured through common consumer-grade audio-recording devices in current medical, behavioral science, business, and computer science research. Specifically, this work provides evidence from a tightly controlled laboratory experiment analyzing 1800 voice samples and subsequent simulations that recording devices with high proximity to a speaker (such as a headset or a lavalier microphone) lead to inflated measures of amplitude compared to a benchmark studio-quality microphone while recording devices with lower proximity to a speaker (such as a laptop or a smartphone in front of the speaker) systematically reduce measures of amplitude and can lead to biased measures of the speaker's true fundamental frequency. We further demonstrate through simulation studies that these differences can lead to biased and ultimately invalid conclusions in, for example, an emotion detection task. Finally, we outline a set of recording guidelines to ensure reliable and valid voice recordings and offer initial evidence for a machine-learning approach to biascorrection in the case of distorted speech signals.

Comparison of In-Person and Online Recordings in the Clinical Teleassessment of Speech Production: A Pilot Study

In certain circumstances, speech and language therapy is proposed in telepractice as a practical alternative to in-person services. However, little is known about the minimum quality requirements of recordings in the teleassessment of motor speech disorders (MSD) utilizing validated tools. The aim here is to examine the comparability of offline analyses based on speech samples acquired from three sources: (1) in-person recordings with high quality material, serving as the baseline/gold standard; (2) in-person recordings with standard equipment; (3) online recordings from videoconferencing. Speech samples were recorded simultaneously from these three sources in fifteen neurotypical speakers performing a screening battery of MSD and analyzed by three speech and language therapists. Intersource and interrater agreements were estimated with intraclass correlation coefficients on seventeen perceptual and acoustic parameters. While the interrater agreement was excellent for most speech parameters, especially on high quality in-person recordings, it decreased in online recordings. The intersource agreement was excellent for speech rate and mean fundamental frequency measures when comparing high quality in-person recordings to the other conditions. The intersource agreement was poor for voice parameters, but also for perceptual measures of intelligibility and articulation. Clinicians who plan to teleassess MSD should adapt their recording setting to the parameters they want to reliably interpret.

Finger Kazoo Intensive Short-term Vocal Therapy: Vocal and Aerodynamic Measurements in Female Teachers

Objectiveto verify the effect after short-term intensive therapy with the Finger Kazoo technique on vocal and aerodynamic measures of dysphonic female teachers. Methodblind randomized clinical trial. Fifteen female teachers without structural disorders of vocal folds and nine with vocal nodules participated in the study groups. Yet, nine female teachers without structural disorders and eight with vocal nodules in the control groups. The following variables were measured pre and post-therapy: minimum and maximum fundamental frequency: forced vital capacity; simple phonic coefficient; compound phonic coefficient; ratio between maximum phonation time of /a/ and expected maximum phonation time. Resultsno statistical significance was observed in the intra and intergroup analyses in any of the measures. Conclusionin this group of female teachers, it was not possible to show a positive effect of short-term and intensive therapy with the Finger Kazoo technique on the vocal measures of minimum and maximum fundamental frequency, forced vital capacity, simple phonic coefficient, compound phonic coefficient, and the relationship between maximum phonation time of /a/ and expected maximum phonation time.

Developing a voice monitoring smartphone app: Acoustic acquisition and processing considerations

With the advent of smartphone technology, there has been an increase in at-home health monitoring. Yet, there are few applications (apps) available to track voice acoustics for those with voice disorders. Therefore, we completed two investigations into the acquisition and processing of the acoustic signal to help develop a voice monitoring app. Study 1: We investigated how microphone distance and phone tilt impact the accuracy of acoustic measures of voice. A total of 58 participants with (n = 47) and without (n = 11) voice disorders completed speech tasks of sustained vowels and the rainbow passage. Concurrent recordings were collected using the participant’s phone, as well as a stationary headset microphone for comparison. We determined that the voice measures of fundamental frequency (Hz), voicing duration (seconds), and cepstral peak prominence (dB) were impervious to phone distance and tilt. Study 2: Focusing on the three acoustic measures from study 1, we investigated the correspondence between acoustic measures attained with clinically available software (e.g., Praat) and those from our own lab-developed algorithms specialized for on-app processing. Preliminary results show strong relationships (r &amp;gt; .90) between the different processing techniques. Further work is needed to understand how participant-specific factors (age, dysphonia severity) may improve algorithm accuracy.

Voice Load in a Music Student Teacher: A Quantitative Case Study in Voice Dosimetry

ABSTRACT The authors examined the voice use of a student teacher in vocal music in the initial 20 instructional meetings of a choir class over two months in a high school choir class. The purpose was to explore voice load during one daily period in the music classroom at the beginning of the student teaching placement to evaluate how and whether voice use changes in the early stage of teacher preparation. Results indicated that measures of fundamental frequency (F0), phonation time, phonation volume, and background noise level varied across measurement periods and according to student teacher activities. As a percentage of the instructional period, phonation time ranged 1.9% to 42%, and was largest in measurement periods beyond the initial days of student teaching. Teacher volume increased modestly across the data collection. Implications are suggested including increased confidence in the student teacher or increased voice misuse by the student teacher.

Acoustic cues associated with Korean sarcastic utterances produced by right- and left-hemisphere damaged individuals

PurposeSarcasm, prevalent in everyday conversation, refers to the use of words that express negative attitudes toward persons or events. Acoustic cues associated with sarcasm have been reported to vary across studies and the relative importance of particular acoustic parameters for signaling sarcasm has not been fully determined. The hemispheric specialization for the production of acoustic cues has been a matter of controversy. This study investigated the possible prosodic cues associated with Korean sarcastic utterances and the differential effect of left hemisphere damage (LHD) or right hemisphere damage (RHD) on the production of acoustic features of Korean sarcastic utterances. MethodTwenty one native speakers of Korean (7 individuals with LHD, 7 individuals with RHD, and 7 healthy controls (HC)) produced six Korean utterances in two different modes: sarcastic and literal. Utterances validated by sarcasm ratings by native listeners were analyzed acoustically utilizing durational and fundamental frequency (F0) measures. ResultsListeners’ ratings and acoustic analyses indicated that sarcastic utterances in Korean were produced with a combination of multiple acoustic cues. Discriminant function analyses and multiple linear regression showed that LHD and RHD differentially affected the production of acoustic cues associated with sarcasm. ConclusionLHD negatively affects the production of durational cues, while RHD negatively affects the production of F0 cues.

An analysis of prosodic boundaries across speaking styles in two varieties of German

Previous research has shown that differences in the marking of prosodic boundaries exist not only between varieties of the same language, but also between speaking styles of the same variety. Our aim is to gain insights into how these two factors interact in the case of German and Austrian German read and conversational speech. Analysing four acoustic cues, representing durational and fundamental frequency (f0) measures, we observed that pause duration was the strongest cue to prosodic boundaries and that f0 reset was the weakest, in both varieties and across speaking styles. In read speech however, we noticed differences between the two varieties in the weighting given to the four cues. We then employed the four investigated acoustic cues for the annotation of the less-resourced variety, by examining ways of exploiting resources from the more well-resourced variety. Testing three automatic approaches for boundary detection, we obtained an overall high performance: 82.4% and 76.6% F-score for read and conversational speech, respectively. Moreover, our results showed that training on more data from the well-resourced variety did not outperform the same system trained on less data from the target variety.

Acoustic voice and spectrographic measures in children with the phonological process of devoicing

IntroductionChildren with speech sound disorders (SSDs) who present the devoicing of plosive and/or fricative sounds may have difficulties with glottal respiratory control. ObjectiveTo analyze acoustic vocal measures, spectrographic aspects and the risk of dysphonia among children with devoicing SDDs and compare the results with those of other groups of children. MethodsTwenty-five boys aged between six and 12 years participated. They were divided into four groups: the SSD-devoicing (PPDG), dysphonia (DG), SSDs other than devoicing (PPOG) and control groups (CG). The vocal tasks were recorded, and perceptual-auditory and acoustic voice analyses were performed. The children's parents answered questions about voice-related aspects (to determine a dysphonia risk score). All data were compared among the groups. ResultsDue to the sample size, an effect size analysis was considered, and the results showed possible differences between the PPDG and the other groups in measures of fundamental frequency (F0), jitter, shimmer, harmonic-to-noise ratio, maximum frequency of harmonic definition and dysphonia risk score. ConclusionsThe PPDG showed a high F0 and abnormal jitter and shimmer values. Although the voices of the children in this group had more harmonics than noise, the maximum frequency for defining the harmonics was very restricted. The PPDG had the lowest dysphonia risk score among all of the groups. Variations in F0, jitter and shimmer may indicate difficulties with controlling vocal adjustments, which appear to be hyperfunctional and not to impact vocal projection or voicing.

Vocal Characteristics of Children With Short Stature Before and After Growth Hormone Treatment

To evaluate the vocal characteristics of children with short stature before and 12 months after growth hormone treatment. This analytical, observational cohort study included 23 children (age 5-11 years) diagnosed with short stature. Children in the short stature group (SSG) were matched (1:1) for age and sex with children with normal growth (normal stature group; NSG). Participants in the SSG underwent assessments before and 12 months after growth hormone treatment, while those in the NSG underwent the same assessments at baseline and 12 months. The assessments included evaluation of (A) vocal characteristics (history, vocal self-assessment, auditory-perceptual evaluation, and acoustic analysis), (B) anthropometry, (C) bone age, and (D) measurement of insulin-like growth factor-1 (IGF-1) levels. Children in the SSG had more vocal complaints (P = 0.026) than those in the NSG. The groups were similar in terms of vocal self-assessment and auditory-perceptual evaluation (P = nonsignificant). Results of acoustic analysis were also similar for fundamental frequency (F 0) and perturbation measures (P for both = nonsignificant). F 0 and speech frequency decreased significantly at 12 months in both groups. F1 values were higher at 12 months in the NSG, while F2 values were significantly higher in the baseline evaluation in boys in the SSG. Children in the SSG compared with those in the NSG presented a greater increase in height measurements at 12 months, although the anthropometric means were lower in both evaluations (P < 0.001). Vocal characteristics in children with short stature before and after treatment with growth hormone are comparable to those in children with normal growth.