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At least 883 records · Page 49Linked to original sources
PubMed1984

Teflon injection in 16 patients with paralytic dysphonia: perceptual and acoustic evaluations.

Sixteen patients with paralytic dysphonia were treated with Teflon injection in the paralyzed vocal fold. Trained voice pathologists rated the pre- and postinjection voices on a 5-point scale for each 11 voice characteristics. Among these, aphonia, breathiness, and hypofunction diminished significantly after injection. The perceptual evaluation was correlated with acoustic data from long-time-average spectrum analysis, fundamental frequency distribution analysis, and waveform perturbation analysis. In this acoustic assessment, systematic changes were found in the long-time-average spectra, which agreed well with the perceptual data. In 12 of 16 patients the voice was both perceptually and acoustically improved after Teflon injection.

Adult↗
PubMed1984

Effects of rise-fall time, frequency, and intensity on the early/middle evoked response.

Auditory evoked responses to tone pips were recorded on 10 normally hearing adults. Tone pips centered at 500 and 2000 Hz with 1, 2, and 4 ms rise-fall times were presented at intensities of 40, 30, 20, and 10 dB nHL. The band-pass of the recording-amplifier system was set to 55 and 3000 Hz. Responses were measured during the first 25 ms following the onset of the stimulus and the first three prominent waves were labeled P10, N15, and P20. The results indicated that varying rise-fall times from 1 to 4 ms had little effect on the detectability of these waves. Consequently, the 4-ms rise-fall time was recommended because of its greater frequency specificity. The number of identifiable responses was similar for both 500 and 2000 Hz for waves P10, N15, and P20. The similarity in the number of detectable responses suggests that any of these waves may be used as a threshold indicator. The acoustic/physiologic mechanisms underlying the latency changes are discussed.

Acoustic Stimulation↗
PubMed1985

Vowel confusions of hearing-impaired listeners under reverberant and nonreverberant conditions.

The effects of reverberation on the perception of vowels and diphthongs were evaluated using 10 subjects with moderate sensorineural hearing losses. Stimuli were 15 English vowels and diphthongs, spoken between/b/and/t/and recorded in a carrier sentence. The test was recorded without and with reverberation (T = 1.2 s). Although vowel confusions occurred in both test conditions, the number of vowels and diphthongs affected and the total number of errors made were significantly greater under the reverberant condition. The results indicated that the perception of vowels by hearing-impaired listeners can be influenced substantially by reverberation. Errors for vowels in reverberation seemed to be related to the overestimation of vowel duration and to a tendency to perceive the pitch of the formant frequencies as being higher than in vowels without reverberation. Error patterns were somewhat individualized among subjects.

Aged↗
PubMed1985

A microcomputer-based wearable biofeedback device to improve transfer of treatment in parkinsonian dysarthria.

Achieving transfer of treatment outside the clinic is a problem for almost all individuals with speech disorders but has been particularly difficult in the treatment of patients with Parkinsonism. Given this situation and the frequency of vocal intensity problems in this population, we developed a wearable biofeedback device that could provide a patient with information about speech intensity outside the clinic. Auditory-perceptual and acoustic analyses were performed on audiotaped samples of reading and spontaneous speech recorded in the clinic pre- and posttreatment and at 10- and 20-week follow-ups. Visual feedback of intensity was integrated with auditory cues from a microcomputer that was then worn outside the clinic. The results indicated that the subject did transfer a substantial portion of clinic improvement to the outside environment while wearing the feedback device and suggest the utility of a microcomputer-based wearable device for assessing treatment effects as well as for improving transfer.

Aged↗
PubMed1988

Acoustic and perceptual measurements of roughness influencing judgments of pitch.

Listeners matched the pitch of 36 clear to severely dysphonic vowels to the frequency of pure tones produced by a signal generator. Mean difference scores on pitch match correlated-.56 with jitter, -51 with jitter ratio, -.57 with spectrographic noise classifications, and -.64 with vocal roughness. Moderately to severely dysphonic vowels received significantly lower pitch match values than clear to mildly dysphonic vowels. Findings suggest that the effect of vocal roughness on pitch should be considered by the clinician who makes use of perceptual judgments.

Adolescent↗
PubMed1989

Acoustic tracking of articulation errors: [r].

The objective of this study was to determine the usefulness of acoustic tracking as a supplement to perceptual judgements during remediation. One child, receiving weekly individual treatment, participated in a drill-and-practice approach to remediation for a single [w]-for-/r/ substitution error. Imitations of consonant-vowel (CV), VCV, and matched /r/ and /w/ sentence stimuli were audiotape recorded. The temporal and spectral characteristics of the recorded stimuli (i.e., the F2 transition rates and F2 values for the changing [r]) were spectrographically tracked and analyzed over a 70-day remediative period. The acoustic data were compared with the perceptual judgments of articulatory change. Generally, as the child's productions moved from the [w] toward the [r], the measured F2 values became higher and the F2 transition rates lowered. Results suggest that acoustic tracking of a child's productions may become a useful tool to augment perceptual tracking. Implications are discussed for the applications of acoustic tracking within clinical practice.

Articulation Disorders↗
PubMed1979

Tempo of spectrum change as a cue in speech-sound discrimination by infants.

Six- to seven-month-old infants were tested on their ability to discriminate among three speech sounds which differed on the basis of formant-transition duration, a major cue to distinctions among stop, semivowel and diphthong classes. The three speech sounds, [see text] were produced in two different ways. The stimuli for one experiment were two-formant synthetic tokens which differed in formant-transition duration. The stimuli for a second experiment was produced with a computer-modification technique which artificially shortened or lengthened the formant-transition portion of a naturally produced [see text], resulting in tokens of [see text]. The discrimination procedure involved visual reinforcement of a head-turn response following a change from a repeating background stimulus to a contrasting stimulus. Infants in both experiments discriminated [see text]; evidence for [see text] discrimination was obtained for the "computer modified" tokens only. These findings are discussed in terms of possible mechanisms underlying speech perception in infancy.

Cues↗
PubMed1979

Acoustic qualities of phonation in young hearing-impaired children.

Monosyllables were recorded from a group of 24 hearing-impaired and 6 normal-hearing children between three to six years of age. Tokens of the syllables /ba/ and /bo/ were placed on listening tapes and a panel of 10 experienced listeners made ratings of relative voice quality. The phonation samples were subjected to both a gross (spectrographic) and a fine (computer-aided) acoustic analysis. The following acoustic characteristics were examined: (1) mean fundamental frequency, (2) duration, (3) mean period-to-period changes in intensity and in fundamental frequency, (4) spectral energy ratio above and below 1000 Hz, and (5) intonation contour. The type of intonation contour appeared to be the most important characteristic separating the better from the poorer deaf speakers. The hearing-impaired subjects produced four different types of deviant intonation contours. In addition, two abnormalities of phonation, diplophonia and breathiness, are described.

Child↗
PubMed1980

Acquisition of the voicing contrast language-delayed and normal-speaking children.

Voicing is a phonological contrast which emerges early in the speech of children. However, the acoustic correlates of the voicing contrast for stop consonants are fairly complex. In the initial position, voicing is cued primarily by the relative timing of articulatory versus laryngeal gestures. In the final position, the duration of the preceding vowel is associated with the voicing contrast of stop consonants. The purpose of this study was to examine the pattern of acquisition of the voicing contrast in the speech of ten children diagnosed as language-delayed in comparison with the acquisition of the voicing contrast by normal speaking children. The language-delayed and normal-speaking children were matched according to mean length of utterance (MLU) and placed in one of Brown's five developmental stages. Each participant was first given a short test, using natural speech, to determine his or her ability to identify minimal pairs differing in the voicing of stop consonants. Those who passed the test were recorded under standard recording conditions repeating 12 test words. The test words contrasted voiced and voiceless stop consonants in initial and final positions. Spectrograms of the three best productions of each word were used to examine voice-onset time for stops in initial position and preceding vowel duration for stops in final position. Although the language-delayed and normal-speaking children showed equivalent linguistic sophistication (as measured by MLU), the language-delayed children's control of the acoustic-phonetic details of the voicing contrast was less mature than that of the normal-speaking children.

Child↗
PubMed1980

Better spectrograms from children's speech. A research note.

A major problem in the spectrographic analysis of children's speech is the poor resolution of formants, which is the result of the widely spaced harmonics of the high fundamental frequency. An attempt has been made to bypass this problem by exciting a child's vocal tract with an artificial larynx, using a fundamental frequency appropriate to a man. This method has promise for tracking formants in children's speech.

Child↗
PubMed1980

A comparative study of speech perception in young severely retarded children and normally developing infants.

The discrimination of minimally paired speech sounds by seven retarded children with a mean age of 3 years, 2 months and a mean IQ of 38.4 was compared with the discrimination performance of eight normally developing 7-month-old infants. Children and infants were tested using the Visually Reinforced Infant Speech Discrimination (VRISD) paradigm in which they were taught to respond with a head turn to a change in a repeating background auditory stimulus. Responses were reinforced by activation of an animated toy. All children proved to be conditionable and both groups evidenced discrimination of the speech contrasts tested. The data suggest that the retarded children have moree difficulty processing a contrast cued by rapid spectral changes (often associated with consonant discrimination) than they do a contrast cued by steady-state spectral information (often associated with the perception of slowly articulated vowels). The normally developing infants did not find rapid spectral cues mor difficult than steady-state cues These results parallel those of Tallal (1976) who found that dynamic cues were specifically difficult for dysphasic children (with normal nonverbal intelligence), but not for linguistically-normal elementary school children.

Child, Preschool↗
PubMed1980

Vocal characteristics of normal speakers and stutterers during choral reading.

It is well known that stutterers experience significant decrements in their stuttering when they read or speak in unison with another person. Recently, Wingate suggested that the act of choral reading or speaking prompts the individual who is following the model speaker to emphasize vocalization and its continuity throughout the utterance. This modified vocalization may then be viewed as the immediate cause of the stutterers' reduced disfluency. To evaluate this hypothesis, ten stutterers and ten normal speakers were tested in a control and choral reading condition. In the former, subjects read in their habitual manner. In the latter, subjects read in unison with a recording of a normal adult male. Subjects' oral readings were audio-taped and then submitted to spectrographic analysis. Measures of vowel duration, peak vocal SPL and continuity of phonation were made and then treated statistically. The major findings of this study indicated that across the two conditions, both groups failed to modify their vocal SPL and continuity of phonation. They did, however, alter their vowel durations. The normal speakers increased theirs by a statistically insignificant amount, while the stutterers significantly shortened theirs. The results that pertained to vocal SPL and vowel durations seemed a function of each group's scores for these measures in the control condition as compared to the values for the same measures that were generated by the model speaker with whom subjects read in unison in the experimental condition. These and other findings and interpretations are discussed further relative to Wingate's "modified vocalization" hypothesis.

Adolescent↗
PubMed1980

The effects of presentation of noise and dental appliances on speech.

The effects of dental appliances on speech were studied when subjects wore the appliances, both in quiet and in the presence of an intense noise. A group of 24 normal-speaking subjects read lists of syllables, words, and sentences and spoke spontaneously in each of six appliance and noise conditions. Several acoustic and perceptual measurements were made in each condition. In general, speech deteriorated when appliances were placed and when noise was presented. The type and amount of speech disruption varied as a function of speech task and aspect of speech. There was no evidence that the effects of appliances on speech differed in quiet and noise conditions. Inter-subject variability was large.

Adult↗
PubMed1981

Auditory discrimination of voiceless fricatives in children.

Auditory discrimination of the voiceless fricatives magnitude of theta f integral of s was studied in 200 subjects between the ages of four and six and a half years. In the test task the subject was asked to remember one of the sounds and then to indicate each time this sound was presented. Two types of errors were analyzed. An error of omission was a failure to identify the remembered sound, and this type of error did not change with age. An error of commission, a failure to discriminate between the remembered sound and one of the other voiceless fricatives, decreased with age. The results are interpreted as support for a theory of the development of auditory perception of speech in which discrimination of some properties in speech, such as relatively weak spectral cues and second formant transitions, have to be learned by a child.

Age Factors↗
PubMed1981

Disambiguation of ditropic sentences: acoustic and phonetic cues.

In a previous study, we demonstrated that listeners were highly successful in identifying the intended meaning of spoken ditropic sentences (those which may carry either a literal or an idiomatic meaning) when speakers were instructed to convey the distinction. The present communication reports on acoustic and phonetic analyses carried out with the goal of identifying cues that distinguished the literal and idiomatic utterances. Certain prosodic differences were observed. Literal utterances were systematically longer than idioms. This was partly due to increased use of pauses, as well as to increased duration of major lexical items. Moreover, literal sentences were typically characterized by greater numbers of pitch contours (discernible rise-fall excursions of fundamental frequency) and open junctures than were idiomatic utterances. In addition to suprasegmental contrasts, articulatory distinctions--corresponding to lento-allegro phonological rules--were also observed. These distinctions directly reflect the structural differences intrinsic to the two types of utterances. A literal sentence is formulated by the organization of constituent words and phrases. Idioms, on the other hand, are holistic units, largely nontransparent to syntactic structure or the usual meaning of the lexical members.

Humans↗
PubMed1981

Detection of tones in band-reject noise.

Three experiments were conducted to investigate the detectability of tonal signals simultaneously presented with computer-generated, long duration (.5 sec), band-reject maskers. In Experiment 1, detectability of a tone of 500, 1000, or 2000 Hz presented at 50 dB SPL was measured as a function of the width of a spectral "notch" symmetrically placed around the tone. A narrow notch resulted in decreased detectability relative to the wide band (zero-notch width) control condition. Further increases in notch width resulted in increased detectability until subjects approached errorless performance. In Experiment 2, psychometric functions were obtained for a 1000-Hz tone presented in four notch-noise conditions. The slopes of the psychometric functions were consistently steeper in the band-reject conditions relative to the zero notch-width condition. These slope differences result in relationships between threshold and notch width that depend upon the region of the psychometric function from which the threshold estimates are obtained. In Experiment 3, the decrease in performance associated with the notch was found to increase in proportion to notch depth. The data suggest that spectral edges placed in the immediate vicinity of a tone reduce the detectability of the tonal signal. This "edge effect" is discussed in relation to two-tone inhibition that has been observed in the auditory nerve.

Acoustic Stimulation↗
PubMed1982

Voice onset time in normal-aged population.

Evidence suggests that the fine motor coordinations required to maintain the articulatory-laryngeal adjustments represented by measures of voice onset time (VOT) should change as a function of normal aging. This descriptive study obtained measures of VOT in healthy elderly subjects as a basis for extending the model of temporal speech control to the later years. Three groups of 10 subjects each were used. Group I was composed of subjects 25-39 years old. Groups 2 and 3 included subjects aged 65-74, and over 75, respectively. Subjects produced 30 tokens of three stimulus words, beat, pete, bead, following a carrier phrase. Wide-band spectrograms were prepared and measured, and the VOT data analyzed statistically. The following conclusions were drawn with respect to mean group age. The means of the VOTs did not differ significantly across subject groups. Standard deviations in the means did differ significantly, variability increased with age, both within subjects and between groups. The minimal separation of the phonemic boundaries for /b/ and /p/ decreased significantly as a function of aging, with the /p/ side of the distribution showing the greatest change.

Adult↗
PubMed1982

A fluent backward talker.

This report documents the ability of a man to reverse the order of segments within words, so quickly that the simultaneous translation of forward speech into reversed speech was possible. Transcriptions of recorded backward speech and several processing tasks were used to clarify this man's profile of unusual linguistic skills. Analyses of the background speech showed evidence of sensitivity to both phonemic and orthographic representations of the utterances.

Adult↗