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Results for “Sound Spectrography”
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An acoustic-speech study of patients who received orthognathic surgery.
Several reports have suggested that orthognathic surgery may influence speech patterns. The purpose of this study was to examine the formant frequency changes of speech following orthognathic surgery in patients whose speech was considered perceptually normal preoperatively and postoperatively. Speech samples were obtained from five patients (three patients with Class II, Division 1 malocclusions and two patients with Class III malocclusions). Significant second-formant frequency shifts were found for the vowel 'e' (as in 'seat'); however, only minor second-formant frequency variations were found for the vowels 'a' (as in 'sat') and 'u' (as in 'suit'). The pattern of formant frequencies before and after surgical treatment suggested that the speakers adjusted their articulation to accommodate the orthognathic surgery. Overall, the data from this study indicate that speech patterns may be reorganized after orthognathic surgery even though speech remains perceptually "normal."
Perception of acoustic correlates of major phrasal units by young infants.
How might young learners parse speech into linguistically relevant units? Sensitivity to prosodic markers of these segments is one possibility. Seven experiments examined infants' sensitivity to acoustic correlates of phrasal units in English. The results suggest that: (a) 9 month olds, but not 6 month olds, are attuned to cues that differentially mark speech that is artificially segmented at linguistically COINCIDENT as opposed to NONCOINCIDENT boundaries (Experiments 1 and 2); (b) the pattern holds across both subject phrases and predicate phrases and across samples of both Child- and Adult-directed speech (Experiments 3, 4, and 7); and (c) both 9 month olds and adults show the sensitivity even when most phonetic information is removed by low-pass filtering (Experiments 5 and (6). Acoustic analyses suggest that pitch changes and in some cases durational changes are potential cues that infants might be using to make their discriminations. These findings are discussed with respect to their implications for theories of language acquisition.
Song acquisition in photosensitive and photorefractory male European starlings.
We tested the ability of 1-year-old European starlings (Sturnus vulgaris) to acquire songs while in different physiological states. Photorefractory males, with low testosterone levels, learned songs as completely and as accurately as photosensitive males in full reproductive condition. This indicates that song acquisition in 1-year-old males does not depend on high levels of androgens. The ability to learn songs during the nonbreeding season may reflect the high song output of potential tutors through most of the year, including the photorefractory period, and may facilitate increases in song repertoire size in adulthood.
Antiphonal duetting and sex hormones in the tropical bush shrike Laniarius funebris (HARTLAUB).
We investigated changes in antiphonal duetting with phases of reproduction and circulating levels of luteinizing hormone, testosterone, and estradiol in slate-colored boubous (Laniarius funebris) breeding in aviaries. Frequency of overall male singing did not vary with reproductive phase while frequencies of female singing and female vocal responses to male song were reduced during incubation and feeding of nestlings. This resulted in significant changes in frequency of duetting. Males sang the sexual song type M1 more often during courtship and nest building than during the nestlings phase. Their territorial song types M2 and M4 did not vary with breeding phase. Females were less responsive to M1 during incubation and to M2 during the nest building and nestlings than during the courtship phase. Plasma levels of luteinizing hormone and testosterone increased in males from the prebreeding to the courtship phase. While testosterone decreased already during nest building and remained low during subsequent phases of reproduction, luteinizing hormone decreased during incubation and feeding of nestlings. Female luteinizing hormone levels were highest during nest building. Female estradiol levels decreased from nest building to incubation and increased again during subsequent nest building. Female testosterone levels were low but not basal and did not vary with phase. Neither the overall male and female singing frequencies nor the frequencies of male song types were correlated with hormonal state. However, female participation in territorial duets M4 correlated positively with their testosterone levels. It is suggested that in this monogamous, duetting species with prolonged pairbonds behavioral cues between the mates are more important than the hormonal state in control of male and female singing.
Androstenedione therapy reinstates normal, not supernormal, song structure in castrated adult male zebra finches.
In previous studies, androstenedione (AE) replacement therapy restored the highest levels and intensities of courtship song displays in castrated male zebra finches of any hormone tested. Furthermore, female zebra finches responded strongly to AE-treated males and preferred intact males given small AE implants to unsupplemented males. In this study, we asked whether AE treatment might alter song structure, since male song is an important cue in mate choice by female zebra finches. Songs of adult males were recorded. The males were then castrated and given AE therapy and recorded again. No differences were found between the courtship or undirected songs males sang before castration and after AE treatment. As in previous studies, the structure of a male's courtship song differed significantly from his undirected song, and the structural differences between these two song types were not altered by AE treatment.
Spectral analysis of muscular sound at low and high contraction level.
The activated muscle generates a low frequency rumbling noise, which is known as the Sound-MyoGram (SMG). Spectral analysis of the SMG is carried out in this work, in order to: (i) check the adequacy of both the Fast Fourier Transform (FFT) and the Maximum Entropy Spectrum Estimation (MESE). Because it is a well known technique, the FFT method is only briefly described, while the philosophy of the MESE method is given in more detail and completed with a description of the recursive algorithm; (ii) select a frequency parameter suitable to describe the SMG. For this purpose two well-defined physiological conditions (20% and 80% Maximal Voluntary Contraction) have been adopted in order to provide a safe reference for the interpretation of the findings. The results show that: (a) both FFT and MESE are adequate to estimate the SMG Power Spectrum; (b) both the mean and the median frequency are suitable parameters, the mean frequency being the more favourable one; (c) the SMG Power Spectrum is a promising tool to study the muscle activation modalities.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.