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PubMed1981

Identification of normal and abnormally rough vowels by spectral noise level measurements.

Our goal in this study was to learn whether vowel spectral noise level (SNL) measurements might differentiate between normal and abnormally rough test vowel samples. The vowel samples studied were obtained originally for two previous investigations. In one study, 20 normal-speaking subjects phonated in isolation each of five test vowels both normally and with simulated abnormal vocal roughness. In the other, 20 subjects who individually presented a laryngeal pathology phonated each of the same test vowels in isolation. The 300 test samples available from the two studies were obtained at one intensity and mouth-to-microphone distance (75 dB SPL at 15 cm). From the original studies, narrow-band (3-Hz) acoustic spectra of the vowel samples and SNL measurements were available. For this study, a mean of 25 noise level measurements per vowel sample served as an SNL index for each test production. Additionally, for this study, the test samples were individually classified dichotomously as normal or as abnormally rough in quality by a panel of nine listeners. Data analysis resulted in the identification of an SNL mean value (termed the SNL "criterion") that appeared to differentiate effectively between the perceptually normal and abnormally rough samples of each test vowel. In general, the findings appeared to support the hypothesis that vowel SNL measurements could be used to identify normal and abnormally rough vowel samples.

Humans↗
PubMed1984

Acoustic measurement of voice quality in central dysphonia.

Speech samples of 14 male and 10 female patients with central dysphonia were examined. Eighteen patients had suffered a severe closed head trauma and the remaining six patients had experienced cerebrovascular accident (CVA). Several parameters were developed in order to find acoustic correlates for three major pathologic voice qualities in central dysphonia. The well know jitter parameter, fundamental period perturbation (PP), was adapted for our purposes and proved to be a good measure for rough voices, though the patients revealed less jitter than in peripheral dysphonia. The vocal onset parameter, time lag of preexhalation (Tb), and the spectral parameter, spectral energy above 5 KHz (A5), classified the breathy voices. Most of the tense voices could be detected by the spectral parameters, spectral energy in the 1-5 KHz range (A1), and variance of spectral energy above 5 KHz (V5). The successful classification of these voice qualities allowed the description of compound pathologic voice types in central dysphonia.

Adolescent↗
PubMed1984

Directional perturbation factors for jitter and for shimmer.

Directional perturbation factors for jitter and shimmer were calculated from the sustained production of the vowels /i/, /a/, and /u/ by 20 adult male and 20 adult female speakers. Directional factors for jitter were less than directional factors for shimmer. Shimmer directional factors for females had greater values than for the male speakers. Speculations on the relationship of directional factors and magnitude factors are made with reference to the laryngeal reflexogenic system. The usefulness of directional factors to early diagnosis of laryngeal disease are discussed.

Adult↗
PubMed1985

Disturbances of the temporal organization of speech following bilateral thalamic surgery in a patient with Parkinson's disease.

This report summarizes a detailed analysis of the speech of a 45-yr-old man who had become dysarthric following bilateral thalamic surgery for the relief of symptoms of Parkinson's disease. His speech was characterized by a rapid rate and a mild-to-moderate articulatory deficit. Intelligibility was markedly reduced. The rapid rate was found to be the result of decreased syllable durations rather than to changes in pause or phrase patterns. Decreased syllable durations resulted from abnormal shortening of vowels. Consonant releases were found to be prolonged. This distorted temporal relationship among speech segments was considered to be an important factor in the patient's poor intelligibility and partially explained why uniform electronic expansion of his speech resulted in only negligible increase in intelligibility. It is hypothesized that this speech disturbance results from the interaction of central "metronomic" abnormality with a peripheral neuromotor articulatory impairment.

Brain Damage, Chronic↗
PubMed1986

Differences in fundamental frequency, jitter, and shimmer among four types of infant vocalizations.

An inaudible voice variable, known to be influenced by stress-arousal in adults, was recently discovered to differ significantly among four situationally defined types of infant vocalizations. Other research suggests that jitter in adults also may be altered by stress-arousal. Further, there is a lack of normative data on jitter and shimmer in infant vocalizations. These findings prompted this study comparing F0, jitter, and shimmer among four situationally defined vocalizations ("pain," "hunger," "fussy," and "cooing") of 2-6-month-old infants. Data showed no significant difference in either jitter or shimmer among the four vocalizations; no significant difference in F0, jitter, or shimmer due to the sex or age of infant; a significant difference in F0 among "hunger," "cooing," and either "pain" or "fussy" vocalizations; and no significant difference in F0 between "pain" or "fussy" cries.

Child Language↗
PubMed1986

The vocal tract model of placement: II. Acoustic aspects.

The technique of "placing" the voice in the throat, head, or elsewhere is used in training singers of operatic quality and in vocal rehabilitation. A vocal tract model of placement has been shown to have perceptual validity (Nichols and Shellenberger, 1985). This study tested its acoustic validity. Line spectra of vowels at different vocal placements were analyzed. We found that Formant 2 reflected changes in vocal placement for both male and female speakers.

Humans↗
PubMed1987

An evaluation of residue features as correlates of voice disorders.

Two experiments were conducted to assess the correlations of residue features with some perceptual properties of voice disorders. First, 90 samples of the vowel /a/ produced by patients with various vocal pathologies were analyzed to obtain the residue features, and severity judgments of these vowel samples were obtained. The results of linear multiple regression analysis indicated that the features were highly correlated with the severity ratings. Second, an attempt was made to correlate the residue features with voice qualities. The features were calculated for the vowel /a/ produced by patients with vocal nodules, vocal fold paralysis, and vocal polyps and by normal talkers. Each vowel sample was rated on ten scales of voice quality. The results revealed high correlations among the quality scales so that discrete subject groups could not be formed. Thus, residue features may be useful in assessing the degree of vocal impairment, but their use as correlates of voice quality must await further research.

Adolescent↗
PubMed1987

Episodic reactive dysphonia: a case study.

This case study exemplifies successful diagnosis through stroboscopic fiberoptic examination, illustrates the critical importance of a careful case history, and demonstrates potential hazards of supposedly benign environmental substances for hypersensitive individuals.

Adult↗
PubMed1989

Phonological space in the speech of the hearing impaired.

The vowels /a/, /i/, and /u/ form the extreme points of vowel triangle in Kannada language. First and second formant frequencies of these vowels were measured to determine the phonological space in the speech of the 30 deaf subjects and 30 normally hearing subjects. The phonological space was found to be reduced in the speech of the hearing-impaired subjects, and the reduction was primarily due to the lowering of the second formant of the vowel /i/. Therapeutic implications have been drawn.

Adolescent↗
PubMed1989

Stability in phonational frequency range.

The purpose of the present study was to investigate the stability of total phonational frequency range, and the stability of the elements from which it is calculated--lowest fundamental frequency and highest fundamental frequency--both within a single day and over a prolonged period. Twenty adult subjects were instructed to produce vowel vocalizations at the extremes of their frequency ranges. Lowest and highest frequencies were converted to semitones, and total range in semitones was calculated. Data were collected three times per day for two days 1-2 months apart. Results revealed that for the average subject, all measures varied by at least several semitones. Further research is needed in order to determine the sources of this intrasubject variability before these measures can be applied to clinical populations.

Adult↗
PubMed1989

Timing in speech: a review of Sanskrit literature and its verification.

The concept of timing in speech as held by the ancient Sanskrit Scholars is described. This has been verified by spectrographically analyzing 109 Sanskrit sentences as spoken by ten Sanskrit speakers. The results seem to partly support the notion of Sanskrit grammarians in that their concept regarding the vowel durations gain support from this study. The information obtained from this study and such reviews could be of great importance in the understanding of human speech production and perception.

Female↗
PubMed1989

A preliminary comparison of flat affect schizophrenics and brain-damaged patients on measures of affective processing.

Flat affect is a major component of schizophrenia and is often also seen in neurological disorders. A preliminary set of comparisons were conducted to delineate neuropsychological mechanisms underlying flat affect in schizophrenia, and new measures are described for the assessment of affective deficits in clinical populations. Subjects were schizophrenic with flat affect (SZs), right brain-damaged (RBD), Parkinson's Disease (PDs), and normal control (NC) right-handed adults. Subjects were administered affective measures of expression and perception in both facial and vocal channels. For both perceptual and expressive tasks the SZs performed significantly less accurately than the NCs and the PDs but did not differ from the RBDs. This was the case for both face and voice. This finding lends support to the speculation that right hemisphere mechanisms, especially cortical ones, may be compromised among schizophrenics with flat affect.

Adult↗
PubMed1989

A fundamental frequency investigation of children ages 6-10 years old.

The fundamental frequency characteristics of 30 children between the ages of 6 and 10 years were investigated in a variety of speech tasks. The results indicated that average fundamental frequency across tasks for the boys is approximately 262 Hz, and for girls approximately 281 Hz. Statistical analysis indicated that there was no significant difference in the fundamental frequency of boys and girls in this age range. High vowels were found to have higher fundamental frequency values than low vowels. Sustained vowels had higher fundamental frequency values than either spontaneous speech or reading for both groups of speakers. The results of this investigation are discussed in terms of maturational processes, and in comparison to corresponding adult information.

Child↗
PubMed1989

Harsh voice: vocal effort perceptual ratings and spectral noise levels of hearing-impaired children.

This study investigated the relationship between spectral noise levels and ratings of perceived vocal effort in the voices of severely to profoundly hearing-impaired children as compared to normal-hearing children, aged 6-11. Spectral noise levels served as an index of the inharmonic (noise) components present from 100 to 2500 Hz for sustained vowels. A nine-point perceptual rating scale was devised as the subjective measure of vocal effort. The severely to profoundly hearing-impaired children could be differentiated on the basis of significantly higher ratings for perceived vocal effort in addition to higher physical measurements of spectral noise levels. Tentative therapeutic implications are discussed.

Child↗
PubMed1990

Dysarthria of motor neuron disease: clinician judgments of severity.

Motor Neuron Disease (MND) is a terminal, demyelinating disease affecting upper- and lower-motor neurons and producing muscular weakness resulting in a characteristic spastic-flaccid dysarthria of speech. The present study investigates the relationship between the temporal-acoustic parameters of the speech of 15 individuals with MND as they relate to the progression of the disease and clinicians' judgments of dysarthria severity. When temporal-acoustic parameters are used to predict the progression of MND, it becomes apparent that victims provide compensatory gestures to mark voicing distinctions. When the same acoustic parameters are used to predict clinician judgments of severity, it is found that clinicians tend to use the same temporal cues that mark actual disease progression. Differences between the two sets of predictions relate to the linguistic systems of both speaker and judge, and the implications of this are discussed.

Adult↗
PubMed1991

Systematic sound preference in phonological disorders: a case study.

Systematic sound preference, where a group of sounds with the same manner of articulation is represented by one or two sounds in the production, is one of the characteristics of children with phonological disorders. This article examines the hypotheses advanced by Weiner (1981) for the phenomenon in the light of the data from a 7-year old Portuguese speaking child. The findings support some of the hypotheses, while providing counter evidence for one of them. They also point to the importance of word position and stress patterns in the systematicity of systematic sound preference.

Articulation Disorders↗
PubMed1991

Toward implementation of a flexible hearing aid measurement system.

An evaluation of a computerized hearing aid measurement system was performed with input and output compression hearing aids stimulated using high-quality audio equipment. The results of the computer measurements were compared to those from a manual technique using conventional laboratory instrumentation. The results from the computerized and manual methods matched very closely. However, the computer system was found to be considerably more flexible than conventional instrumentation and was much easier to use.

Equipment Design↗