Hearing Aid Use and Auditory Verbal Therapy Improve Voice Quality of Deaf Children

BackgroundAdequate phonation is self-regulated by auditory feedback. Children with bilateral profound hearing loss (PHL) lack this feedback resulting in abnormal voice. Adequate hearing aid use and auditory-verbal therapy (AVT) may improve voice quality in deaf children.ObjectiveTo study whether hearing aid use and AVT approach improve acoustic parameters of voice of children with bilateral PHL.Materials and methodsNineteen children with bilateral PHL were studied. Age range 2–5 years (X = 53.04 months; SD = 9.54). All children were fitted with hearing aids according to auditory testing and they underwent a 1-year auditory habilitation period using the AVT approach. Acoustic analysis of voice including F0, shimmer, and jitter was performed at the onset and at the end of the auditory habilitation period. Final acoustic data were compared to a matched control group of 19 children, age range 2–5 years (X = 52.85; SD = 9.74) with normal hearing.ResultsMean fundamental frequency (F0) was significantly increased after AVT intervention. Shimmer and jitter significantly (P < 0.05) improved after the intervention period. However, despite the improvements, mean F0 at the end of the intervention period was still significantly (P < 0.05) decreased as compared to controls. Also, mean shimmer and jitter at the end of the habilitation period were still significantly (P < 0.05) higher as compared to controls.ConclusionsThe results of this preliminary study suggest that hearing aid use and auditory habilitation with AVT approach improved acoustic voice parameters of children with PHL. However, acoustic parameters persisted abnormal as compared to matched normal hearing controls. AVT approach and regular hearing aid use seem to be safe and reliable clinical tools for improving voice quality of children with PFL.     

Where Is a Singer''s Voice if It Is Placed “Forward”?

Singing teachers sometimes characterize voice quality in terms of "forward" and "backward" placement. In view of our traditional knowledge about voice production it is hard to explain any possible acoustic or articulatory differences between the voices so "placed." The analysis of the teachers' expert opinions demonstrates that, in general, a voice placed "forward" indicates a desirable quality that students should attain by the end of their studies. Productions that were perceived as "forward" and "backward" were selected from the listening test. The acoustic analysis of those productions reveals that the voice quality in the case of "forward" placement correlates with higher frequencies of the second (F2) and third (F3) formants, as well as with a more salient "singer's formant" in the voice. The five basic vowels were included in the investigation.     

Voice of Postradiotherapy Nasopharyngeal Carcinoma Patients: Evidence of Vocal Tract Effect

This study was aimed at identifying acoustic and physiological measures useful for monitoring voice changes in postnasopharyngeal patients with nonlaryngeal malignancies, and providing evidences of vocal tract effect on voice through comparisons between individuals with and without intact vocal tract. Simultaneous acoustic-electroglottographic signals recorded during phonation of vowels /i/ and /a/ sustained at habitual, high, and low pitch levels were compared among 10 postradiotherapy patients with nasopharyngeal carcinoma (NPC), 10 voice patients (VPs) with intact vocal tract, and 10 healthy individuals with normal voice (NORM). Results from a series of discriminant analyses revealed that the NPC group generally exhibited lower signal-to-noise (SNR) and open quotient (OQ) and higher Formant 1 frequency (F(1)) and speed quotient (SQ) than the NORM group. Unlike both VP and NORM groups, the NPC group failed to show a pitch effect on all voice measures, including OQ, SQ, percent jitter, percent shimmer, and SNR, suggesting an effect of radiotherapy and/or vocal tract on laryngeal behaviors. For the vowel /i/, on the other hand, only the NPC and NORM groups showed a pattern of pitch-dependent F(1) raising, a reflection of increased pharyngeal narrowing. These findings suggested that the pitch effect on laryngeal behaviors differed not only between individuals with intact vocal tract and those without but also between those with structural and dynamic changes of vocal tract.     

Relationship between subjective voice complaints and acoustic parameters in female teachers'' voices

The aim of the study was to identify the acoustic correlates of female teachers' subjective voice complaints by recording their voices in their working environment. The subjects made recordings during lessons (N = 10) and breaks (N = 11). The subjects were divided into 2 groups: those with few voice complaints (FC group) and those with many voice complaints (MC group). The speech sample made in the breaks was maximally sustained /a/, from which fundamental frequency (F0), jitter, and shimmer were analyzed. The classroom samples were analyzed for F0, sound pressure level (SPL), and F0 time (the active vibration time of the vocal folds). Additionally, an index for assessing voice loading is presented. The results revealed a tendency of the MC group to have higher F0 and lower SPL and perturbation values than the FC group. The index values correlated moderately with the subjective vocal complaints.     

Combined Signal Processing Based Techniques and Feed Forward Neural Networks for Pathological Voice Detection and Classification

This paper presents the pathological voice detection and classification techniques using signal processing based methodologies and Feed Forward Neural Networks (FFNN). The important pathological voices such as Autism Spectrum Disorder (ASD) and Down Syndrome (DS) are considered for analysis. These pathological voices are known to manifest in different ways in the speech of children and adults. Therefore, it is possible to discriminate ASD and DS children from normal ones using the acoustic features extracted from the speech of these subjects. The important attributes hidden in the pathological voices are extracted by applying different signal processing techniques. In this work, three group of feature vectors such as perturbation measures, noise parameters and spectral-cepstral modeling are derived from the signals. The detection and classification is done by means of Feed Forward Neural Network (FFNN) classifier trained with Scaled Conjugate Gradient (SCG) algorithm. The performance of the network is evaluated by finding various performance metrics and the the experimental results clearly demonstrate that the proposed method gives better performance compared with other methods discussed in the literature.     

The prioritization of voice fundamental frequency or formants in listeners' assessments of speaker size, masculinity, and attractiveness

Key features of the voice--fundamental frequency (F(0)) and formant frequencies (Fn)--can vary extensively among individuals. Some of this variation might cue fitness-related, biosocial dimensions of speakers. Three experiments tested the independent, joint and relative effects of F(0) and Fn on listeners' assessments of the body size, masculinity (or femininity), and attractiveness of male and female speakers. Experiment 1 replicated previous findings concerning the joint and independent effects of F(0) and Fn on these assessments. Experiment 2 established frequency discrimination thresholds (or just-noticeable differences, JND's) for both vocal features to use in subsequent tests of their relative salience. JND's for F(0) and Fn were consistent in the range of 5%-6% for each sex. Experiment 3 put the two voice features in conflict by equally discriminable amounts and found that listeners consistently tracked Fn over F(0) in rating all three dimensions. Several non-exclusive possibilities for this outcome are considered, including that voice Fn provides more reliable cues to one or more dimensions and that listeners' assessments of the different dimensions are partially interdependent. Results highlight the value of first establishing JND's for discrimination of specific features of natural voices in future work examining their effects on voice-based social judgments.     

The acoustic bases for gender identification from children's voices.

The purpose of this study was to examine the acoustic characteristics of children's speech and voices that account for listeners' ability to identify gender. In Experiment I, vocal recordings and gross physical measurements of 4-, 8-, 12-, and 16-year olds were taken (10 girls and 10 boys per age group). The speech sample consisted of seven nondiphthongal vowels of American English (/ae/ "had," /E/ "head," /i/ "heed," /I/ "hid," /a/ "hod," /inverted v/ "hud," and /u/ "who'd") produced in the carrier phrase, "Say /hVd/ again." Fundamental frequency (f0) and formant frequencies (F1, F2, F3) were measured from these syllables. In Experiment II, 20 adults rated the syllables produced by the children in Experiment I based on a six-point gender rating scale. The results from these experiments indicate (1) vowel formant frequencies differentiate gender for children as young as four years of age, while formant frequencies and f0 differentiate gender after 12 years of age, (2) the relationship between gross measures of physical size and vocal characteristics is apparent for at least 12- and 16-year olds, and (3) listeners can identify gender from the speech and voice of children as young as four years of age, and with respect to young children, listeners appear to base their gender ratings on vowel formant frequencies. The findings are discussed in relation to the development of gender identity and its perceptual representation in speech and voice.     

Pitch (F0) and formant profiles of human vowels and vowel-like baboon grunts: the role of vocalizer body size and voice-acoustic allometry

Key voice features--fundamental frequency (F0) and formant frequencies--can vary extensively between individuals. Much of the variation can be traced to differences in the size of the larynx and vocal-tract cavities, but whether these differences in turn simply reflect differences in speaker body size (i.e., neutral vocal allometry) remains unclear. Quantitative analyses were therefore undertaken to test the relationship between speaker body size and voice F0 and formant frequencies for human vowels. To test the taxonomic generality of the relationships, the same analyses were conducted on the vowel-like grunts of baboons, whose phylogenetic proximity to humans and similar vocal production biology and voice acoustic patterns recommend them for such comparative research. For adults of both species, males were larger than females and had lower mean voice F0 and formant frequencies. However, beyond this, F0 variation did not track body-size variation between the sexes in either species, nor within sexes in humans. In humans, formant variation correlated significantly with speaker height but only in males and not in females. Implications for general vocal allometry are discussed as are implications for speech origins theories, and challenges to them, related to laryngeal position and vocal tract length.     

Aerodynamic and Acoustic Characteristics of Voice in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a multisystem disorder caused by DNA abnormalities involving chromosome 15. Major characteristics are infant hypotonia, hypogonadism, mental retardation, a short stature, atypical facial appearance, and the onset of obesity due to insatiable hunger in early childhood. Also, speech and language abnormalities have been reported including voice disorders. These have seldom been studied in detail, however. This paper reports the results of an acoustic and aerodynamic investigation of the voice in 22 individuals with PWS. Two age groups were distinguished, a group of children [chronological age (CA) 6 years, 7 months through 11 years, 7 months; total intelligence quotient (TIQ) 40-88] and a group of adolescents and adults (CA 17 years, 1 month through 29 years, 5 months; TIQ 41-94). Both aerodynamic and acoustic parameters were obtained and compared with normative data from the Belgian Study Group on Voice Disorders. It was found that voice difficulties do commonly occur in individuals with PWS including impairment of frequency levels, voice quality, and poor aerodynamic capabilities.     

Clinical Analysis of Voice Change as a Parameter of Premenstrual Syndrome

We have evaluated the relationship between voice change and premenstrual syndrome (PMS) by comparing acoustic measurements made during the follicular phase and the premenstrual phase. Twenty-eight women were followed for 2 months for this study. Each participant was asked to produce an /a/ sound for 5 seconds at the midfollicular phase of the menstrual cycle and then 2-3 days before menstruation. Each voice sample was stored and analyzed by the Dr. Speech Science program. The voice data collected from all subjects during the two phases were compared. After that, the subjects were divided into a PMS-positive and PMS-negative group according to the criteria cited in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV); the voice data from each group were compared separately between the two phases. There was no significant difference in the acoustic parameters between the two phases in all subjects (N = 28). In the PMS-positive group (N = 16), jitter was significantly increased during the premenstrual phase compared to the follicular phase (p = 0.048). The patient's PMS score was not correlated with the severity of voice change. We conclude that the change of voice parameter was objectively identified in the PMS-positive group, therefore more careful voice habituation is required during the premenstrual phase in that group.     

The Speaker's Formant

The current study concerns speaking voice quality in two groups of professional voice users, teachers (n = 35) and actors (n = 36), representing trained and untrained voices. The voice quality of text reading at two intensity levels was acoustically analyzed. The central concept was the speaker's formant (SPF), related to the perceptual characteristics "better normal voice quality" (BNQ) and "worse normal voice quality" (WNQ). The purpose of the current study was to get closer to the origin of the phenomenon of the SPF, and to discover the differences in spectral and formant characteristics between the two professional groups and the two voice quality groups. The acoustic analyses were long-term average spectrum (LTAS) and spectrographical measurements of formant frequencies. At very high intensities, the spectral slope was rather quandrangular without a clear SPF peak. The trained voices had a higher energy level in the SPF region compared with the untrained, significantly so in loud phonation. The SPF seemed to be related to both sufficiently strong overtones and a glottal setting, allowing for a lowering of F4 and a closeness of F3 and F4. However, the existence of SPF also in LTAS of the WNQ voices implies that more research is warranted concerning the formation of SPF, and concerning the acoustic correlates of the BNQ voices.     

Measuring positive and negative affect in the voiced sounds of African elephants (Loxodonta africana)

As in other mammals, there is evidence that the African elephant voice reflects affect intensity, but it is less clear if positive and negative affective states are differentially reflected in the voice. An acoustic comparison was made between African elephant "rumble" vocalizations produced in negative social contexts (dominance interactions), neutral social contexts (minimal social activity), and positive social contexts (affiliative interactions) by four adult females housed at Disney's Animal Kingdom?. Rumbles produced in the negative social context exhibited higher and more variable fundamental frequencies (F(0)) and amplitudes, longer durations, increased voice roughness, and higher first formant locations (F1), compared to the neutral social context. Rumbles produced in the positive social context exhibited similar shifts in most variables (F(0 )variation, amplitude, amplitude variation, duration, and F1), but the magnitude of response was generally less than that observed in the negative context. Voice roughness and F(0) observed in the positive social context remained similar to that observed in the neutral context. These results are most consistent with the vocal expression of affect intensity, in which the negative social context elicited higher intensity levels than the positive context, but differential vocal expression of positive and negative affect cannot be ruled out.     

Documentation of progress in voice therapy: perceptual, acoustic, and laryngostroboscopic findings pretherapy and posttherapy

The effect of voice therapy in a group of chronically dysphonic patients with diverse diagnoses was studied according to the normal clinical procedure. The results were evaluated by perceptual rating, acoustic analysis, and the assessment of laryngostroboscopic recordings. Although the group effects for the differences between posttherapy and pretherapy data were clearly significant, the effects of voice therapy for the individual patients were divergent. For each of the three evaluation methods, a significant improvement was found for about 40% to 50% of the patients. The diversity of the therapy outcome among the patients could not be explained by the pretherapy status nor by age, gender, or diagnosis groups. In general, the perceptual ratings and the acoustic parameters from the baseline data were clearly correlated. However, these characterizations of the voice were only moderately correlated with the visual evaluation of the vocal fold vibrations. Relations among the three evaluation tools for the changes caused by voice therapy were very weak. The low correlation among the three methods suggests that a multidimensional evaluation of the voice is necessary to give a complete picture of the therapy outcome.     

Aerodynamic and acoustic voice measurements of patients with vocal nodules: variation in baseline and changes across voice therapy.

An important clinical issue concerns the efficacy of current voice therapy approaches in treating voice disorders, such as vocal nodules. Much research focuses on finding reliable methods for documentation of treatment results. In this second treatment study of ten patients with vocal nodules, who participated in a behaviorally based voice therapy program, 11 aerodynamic (transglottal air pressure and glottal waveform) and acoustic (spl, f0, and spectrum slope) measures were used. Three pretherapy baseline assessments were carried out, followed by one assessment after each of five therapy phases. Measurements were made of two types of speech materials: Strings of repeated /pae/ syllables and sustained /ae/ phonations in two loudness conditions: comfortable loudness and loud voice. The data were normalized using z-scores, which were based on data from 22 normal subjects. The results showed that the aerodynamic measures reflected the presence of vocal pathology to a higher degree than did the acoustic spectral measures, and they should be useful in studies comparing nodule and normal voice production. Large individual session-to-session variation was found for all measures across pretherapy baseline recordings, which contributed to nonsignificant differences between baseline and therapy data.     

Fundamental frequency correlates of stop consonant voicing and vowel quality in the speech of preadolescent children

Fundamental frequency (F0) and voice onset time (VOT) were measured in utterances containing voiceless aspirated [ph, th, kh], voiceless unaspirated [sp, st, sk], and voiced [b, d, g] stop consonants produced in the context of [i, e, u, o, a] by 8- to 9-year-old subjects. The results revealed that VOT reliably differentiated voiceless aspirated from voiceless unaspirated and voiced stops, whereas F0 significantly contrasted voiced with voiceless aspirated and unaspirated stops, except for the first glottal period, where voiceless unaspirated stops contrasted with the other two categories. Fundamental frequency consistently differentiated vowel height in alveolar and velar stop consonant environments only. In comparing the results of these children and of adults, it was observed that the acoustic correlates of stop consonant voicing and vowel quality were different not only in absolute values, but also in terms of variability. Further analyses suggested that children were more variable in production due to inconsistency in achieving specific targets. The findings also suggest that, of the acoustic correlates of the voicing feature, the primary distinction of VOT is strongly developed by 8-9 years of age, whereas the secondary distinction of F0 is still in an emerging state.     

Objective and Subjective Evaluation of Voice Quality in Multiple Sclerosis

The aim of this comparative, controlled, cross-sectional study is to evaluate the voice quality in patients with multiple sclerosis (MS) by subjective and objective methods. Female patients with MS (n=27) and age- and sex-matched healthy controls (n=27) were included in this study. Vocal functions were evaluated by a multidimensional set composed of videolaryngostroboscopic examination, acoustic analysis, and subjective measurements (GRBAS and "Voice Handicap Index"). Jitter percent, shimmer percent, and soft phonation index (SPI) values were higher in MS patients compared to controls (Jitt, P=0.001; Shim, P=0.033; SPI P<0.0001). Maximum phonation time was significantly shorter for MS patients compared to controls (P<0.0001). Stroboscopic examination revealed that 16 out of 27 MS patients have a "posterior chink" as glottic closure pattern with higher SPI values (40%). Noise to harmonic ratio (NHR) and mean fundamental frequency (F0) values were similar for MS and control groups (NHR, P=0.737; F0, P=0.976). In this study, most of the MS patients had dysphonia due to weakness of voice. MS tends to worsen acoustic parameters including fundamental frequency, SPI, and jitter values. These results are consistent with the more asthenic voice quality observed in MS group.     

Common Practices of Voice Therapists in the Evaluation of Patients

This study surveys voice therapists regarding common diagnostic practices in patients referred for therapy with the diagnosis of muscle tension dysphonia (broadly defined as the "hyperfunctional" component of the dysphonia). Through postings on the e-mail list of the ASHA special interest division on voice, speech pathologists with at least 3 years' experience in stroboscopy and acoustic instrumentation were invited to complete the survey. Results from 53 completed surveys demonstrated that voice quality and patient self-perception are the sole assessments performed by all therapists. Voice quality, observation of body posture and movement, and probing the patient's ability to alter voice production are each significantly more likely to be performed than the more objective stroboscopic, acoustic, aerodynamic, and EGG assessments. Further, the tasks of defining specific therapy session goals and helping the patient to achieve a particular target skill are considered best served by measures of vocal quality, observation of body position and movement, and judging the patient's ability to alter voice production. For definition of the overall therapy goal, stroboscopy and patient perception scales are added to all of the subjective assessment measures as being important. Acoustic data are considered most important for patient reinforcement and outcomes assessment. Implications of these findings are discussed, and topics for further exploration are identified.     

Effects of Vocal Constitution and Autonomic Stress-Related Reactivity on Vocal Endurance in Female Student Teachers

Several studies revealed a high percentage of voice problems in future teachers. The influence of vocal constitution on the vocal endurance is, however, still unclear. The goal of this study was to evaluate whether the increase of voice fundamental frequency (F0) during teaching is caused by (1) autonomic regulation patterns under stress, (2) anxiety as an emotional factor, or (3) limitations in voice constitution. Thirty-three subjects with either normal voice constitution (n = 15, group 1) or constitutional hypofunction (n = 18, group 2) assessed by voice range profile measurements were enrolled in this study. Furthermore, they underwent a standardized baseline test to register selected autonomic test parameters and were classified into autonomic outlet types (AOT) as proposed by Johannes et al. Later the subjects were examined during 1 hour of teaching (field study). The parameters tested included heart rate, pulse transition time, finger temperature, and voice fundamental frequency. To measure situational anxiety and general anxiety proneness, a state-trait anxiety inventory was taken. Eleven subjects per group were identified as autonomic stable (AOT 1), two per group as responding cardiovascularly (AOT 2), and two of group 1 and four of group 2, respectively, as having higher heart rate and higher blood pressure responses to stress (AOT 4). One subject had to be excluded because of missing data. However, statistical analyses showed no differences between AOT groups regarding the voice constitution groups. Increased fundamental frequencies of speaking voice after 30 and 45 minutes of teaching were found in group 2 (constitutional hypofunction). No effect of state or trait anxiety on voice endurance could be detected. Thus, the increase of fundamental frequency of voice has to be regarded as a consequence of vocal fatigue. A constitutionally weak voice seems to be a risk factor for developing a professional voice disorder.     

The relationship of vocal tract shape to three voice qualities

Three-dimensional vocal tract shapes and consequent area functions representing the vowels [i, ae, a, u] have been obtained from one male and one female speaker using magnetic resonance imaging (MRI). The two speakers were trained vocal performers and both were adept at manipulation of vocal tract shape to alter voice quality. Each vowel was performed three times, each with one of the three voice qualities: normal, yawny, and twangy. The purpose of the study was to determine some ways in which the vocal tract shape can be manipulated to alter voice quality while retaining a desired phonetic quality. To summarize any overall tract shaping tendencies mean area functions were subsequently computed across the four vowels produced within each specific voice quality. Relative to normal speech, both the vowel area functions and mean area functions showed, in general, that the oral cavity is widened and tract length increased for the yawny productions. The twangy vowels were characterized by shortened tract length, widened lip opening, and a slightly constricted oral cavity. The resulting acoustic characteristics of these articulatory alterations consisted of the first two formants (F1 and F2) being close together for all yawny vowels and far apart for all the twangy vowels.     

Acoustic Signal Typing for Evaluation of Voice Quality in Tracheoesophageal Speech

SUMMARY: Because of the aperiodicity of many tracheoesophageal voices, acoustic analysis of the tracheoesophageal voice is less straightforward than that of the normal voice. This study presents the development and testing of an acoustic signal typing system based on visual inspection of a narrow-band spectrogram that can be used by researchers for classification of voice quality in tracheoesophageal speech. In addition to this classification system, a selection of acoustic measures [median fundamental frequency, standard deviation of fundamental frequency, jitter, percentage of voiced (%Voiced), harmonics-to-noise ratio (HNR), glottal-to-noise excitation (GNE) ratio, and band energy difference (BED)] was computed to provide more insight into the acoustic components of tracheoesophageal voice quality. For clinical relevance, relationships between the acoustic signal types and an overall judgment of the voice were investigated as well. Results showed that the four acoustic signal types form a good basis for performing more acoustic analyses and give a good impression of the overall quality of the voice.