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At least 127 records · Page 7Linked to original sources

PubMed1989

Characterizing sentence intonation in a right hemisphere-damaged population.

Current production studies present a mixed view of right hemisphere-damaged (RHD) patients' ability to produce normal sentence intonation. The present study characterized the sentence intonation of RHD patients, focusing on a greater number of acoustic parameters than past works, and relying on more naturally elicited speech samples through use of a story completion task. Eight RHD speakers and seven nonneurological control subjects produced declarative and imperative sentences as well as yes-no and wh-questions. Slope of F0 change, linearity of pitch contour, and variance of F0 points were calculated for each utterance as a whole, as well as for the preterminal and the terminal contour separately. RHD contours were less linear and flatter in F0 decline than normal controls for the declarative sentences. The patients' yes-no questions also differed from normal productions, displaying smaller F0 dispersion around a mean F0. Preterminal range values were more restricted for patients' utterances of yes-no questions, while terminal properties between groups differed for three of the four sentence types examined. The present results suggest some disturbance in the patients' ability to manipulate fundamental frequency across sentential domains. These data are discussed in terms of current theories of a general dysprosody in RHD patients.

Brain↗

PubMed1989

Dysprosody in Broca's aphasia: a case study.

A detailed acoustic analysis of timing, intensity, and fundamental frequency (F0) at different levels of linguistic structure was conducted on the speech output of a Broca's aphasic who was a native speaker of Thai. Timing was measured with respect to syllables, phrases, and sentences in connected speech. Intensity variation at the sentence level was measured in connected speech. F0 variation associated with the five Thai tones was measured in both isolated words and connected speech. Results indicated that timing was differentially impaired depending upon complexity of articulatory gesture and size of the linguistic structure. Timing, as well as intensity, was aberrant at the sentence level. In contrast, F0 contours of the five tones were spared at all levels of linguistic structure. Findings are interpreted to support the view that dysprosody in Broca's aphasia is more applicable to speech timing than to F0.

Aphasia↗

PubMed1990

Temporal dimensions of consonant and vowel production: an acoustic and CT scan analysis of aphasic speech.

This study explored a number of temporal (durational) parameters of consonant and vowel production in order to determine whether the speech production impairments of aphasics are the result of the same or different underlying mechanisms and in particular whether they implicate deficits that are primarily phonetic or phonological in nature. Detailed analyses of CT scan lesion data were also conducted to explore whether more specific neuroanatomical correlations could be made with speech production deficits. A series of acoustic analyses were conducted including voice-onset time, intrinsic and contrastive fricative duration, and intrinsic and contrastive vowel duration as produced by Broca's aphasics with anterior lesions (A patients), nonfluent aphasics with anterior and posterior lesions (AP patients), and fluent aphasics with posterior lesions (P patients). The constellation of impairments for the anterior aphasics including both the A and AP patients suggests that their disorder primarily reflects an inability to implement particular types of articulatory gestures or articulatory parameters rather than an inability to implement particular phonetic features. They display impairments in the implementation of laryngeal gestures for both consonant and vowel production. These patterns seem to relate to particular anatomical sites involving Broca's area, the anterior limb of the internal capsule, and the lowest motor cortex areas for larynx and tongue. The posterior patients also show evidence of subtle phonetic impairments suggesting that the neural instantiation of speech may require more extensive involvement, including the perisylvian area, than previously suggested.

Aged↗

PubMed1990

Effects of speech rate on the absolute and relative timing of apraxic and conduction aphasic sentence production.

The purpose of this investigation was to provide a constructive replication of the Kent and McNeil (1987, In Phonetic approaches to speech production in aphasia and related disorders. San Diego: College-Hill Press) study of the speech timing characteristics of apraxic and conduction aphasic speakers. Acoustic analysis was used to obtain absolute utterance durations, segment durations, and vowel formant trajectories from utterances produced under control, fast, and slow rate conditions. Segment-to-whole ratios and slope values were calculated. Results support the hypothesis presented by Kent and McNeil (1987) that there is a phonetic-motoric component contributing to the speech patterns of both the apraxic and conduction aphasic speakers sampled. Theories of rate control in normal and disordered speakers are discussed.

Aged↗

PubMed1990

Dysarthria in Friedreich disease.

Perceptual judgments have previously been used to rate the speech of patients with Friedreich disease. This study attempted to define speech patterns of dysarthria in Friedreich disease using acoustic analyses. The results from 14 patients indicated sudden variations in fundamental frequency and intensity, variability of segment durations, slowness of speech, and low diadochokinetic rate.

Adult↗

PubMed1990

Word-to-word variation in ERP component latencies: spoken words.

Data were collected shedding light on the brain electrical activity underlying word recognition. Subjects listened to a list of 48 spoken words in six random orders under two instructional sets: first to "think about the meanings of the words," and second, to learn the list. The scalp EEG associated with hearing and identifying the words was recorded at F3, F4, Cz, P3, P4, Pz, and Oz. Standard within-subjects time-locked averaging across words showed a late negative-positive complex with N2-P3 topography, the negative component peaking around 480 msec, the positive component peaking around 830 msec. Averaging within words across subjects uncovered considerable latency variability in both components. Within-word N2 and P3 component latencies covaried with word durations and with the "recognition points" predicted for the words by the "cohort theory" of word recognition. N2 latencies corresponded closely to the "N400" effect elicited with semantically incongruous sentence-final spoken words. Implications for ERP investigations of language processing are discussed.

Adult↗

PubMed1991

Functional lateralisation of pitch accents and intonation in Norwegian: Monrad-Krohn's study of an aphasic patient with altered "melody of speech".

The present article provides a linguistic analysis of Monrad-Krohn's famous description of a patient with deviant prosody (1947). Monrad-Krohn found it particularly striking that the patient's "melody of speech" had been damaged although her musical abilities showed no impairment. The patient had suffered a traumatic motor aphasia as the result of a shrapnel wound in Broca's area. In East Norwegian, accented syllables are associated with one of two pitch patterns, either a fall in pitch or a low-level pitch. The patient had trouble producing the distinction between these two accents. Monrad-Krohn's description also suggests that she may have accented words in contexts where they should have been unaccented, with the result that these syllables (erroneously) received one of the two pitch patterns. It is suggested that her apparently deviant sentence intonation could, in some cases, be the "secondary" result of a tendency to produce full vowels in positions where a reduced vowel would be expected, thus abnormally prolonging an otherwise appropriate rising pitch pattern.

Aphasia, Broca↗

PubMed1983

Non-invasive aneurysm detection using digital signal processing.

The attributes and performance expectations of a relatively low cost, non-invasive, aneurysm detection system have been studied. The developed system required that bio-acoustic data be captured at the patients' eyes, conditioned, transformed into the frequency domain, and analysed in some systematic fashion. It was admitted that the signal transducers were in need of improvement. Several low cost spectral analysers were built and tested. This system transformed the patient's bio-acoustic signal into a power spectrum. Features, representative of the patient's medical state, were extracted from the power spectrum and were input to a double-linked tree structure. Together with the medical class information, the structure can be searched to find the best statistical estimate of a patient's medical status. Experiment on generated and patient data, support the validity of the chosen diagnostic scheme.

Adult↗

PubMed1989

Role of natural frequency of bone as a guide for detection of bone fracture healing.

The natural frequency of bone is studied in normal and fractured bones, in vitro as well as in vivo, by recording the outputs of microphone pick-ups, attached at proximal and distal ends to the bone defect. Natural frequency of bone is determined for an optimum output displayed on a cathode ray oscilloscope with respect to different stress wave frequencies. A comparative study of normal and fractured bone in vivo in 25 patients was made to diagnose the size of the fracture and its rate of healing. The natural frequency and intensity of sound in the injured bone was reduced while the output voltage increased with respect to the normal bone. The investigation reports a simple, reliable and rapid technique for the assessment of bone fracture.

Animals↗

PubMed1992

The Dynamic Dento-palatography System: a new approach for evaluating speech.

The assessment of speech in patients with craniofacial anomalies is important to develop appropriate treatment strategies to optimize this aspect of oropharyngeal function. The Dynamic Dento-palatography System which uses multi-electrode array sensors to detect tongue position during articulation is described. Three levels of the speech chain, articulatory, auditory and acoustic, may be analysed in an integrated fashion using this instrument; preliminary results are described. These studies suggest that the quality of speech sounds such as 's' and 't' improve post-operatively.

Dental Arch↗

PubMed1990

Selective impairment of song learning following lesions of a forebrain nucleus in the juvenile zebra finch.

Area X, a large sexually dimorphic nucleus in the avian ventral forebrain, is part of a highly discrete system of interconnected nuclei that have been implicated in either song learning or adult song production. Previously, this nucleus has been included in the song system because of its substantial connections with other vocal control nuclei, and because its volume is positively correlated with the capacity for song. In order to directly assess the role of Area X in song behavior, this nucleus was bilaterally lesioned in both juvenile and adult zebra finches, using ibotenic acid. We report here that lesioning Area X disrupts normal song development in juvenile birds, but does not affect the production of stereotyped song by adult birds. Although juvenile-lesioned birds were consistently judged as being in earlier stages of vocal development than age-matched controls, they continued to produce normal song-like vocalizations. Thus, unlike the lateral magnocellular nucleus of the anterior neostriatum, another avian forebrain nucleus implicated in song learning, Area X does not seem to be necessary for sustaining production of juvenile song. Rather, the behavioral results suggest Area X is important for either the acquisition of a song model or the improvement of song through vocal practice.

Animals↗

PubMed1992

Auditory feedback is necessary for the maintenance of stereotyped song in adult zebra finches.

Although songbirds rely on auditory input for normal song development, many species eventually attain adult song patterns that are thought to be maintained without reference to auditory feedback. In such species, it is believed that a central motor program for song is established when the stereotyped adult song pattern is achieved. However, we report here that in the Australian zebra finch, stereotyped song patterns gradually change in adult males following bilateral cochlear removal. By 16 weeks after surgery, deaf birds accurately reproduced only 36% of the song syllables produced prior to surgery. Moreover, on average, the phonology of over 50% of the syllables produced by deaf birds was either only slightly similar or unlike the phonology of any syllable produced prior to surgery. In contrast, control birds accurately retained over 90% of their syllables over a comparable time period and less than 5% of their syllables was unmatched or only slightly similar in phonology to previously recorded syllables. In many of the deafened birds, changes in song patterns were not evident until 6-8 weeks after surgery. These data indicate that continued auditory input is necessary to maintain the patterns of neural organization supporting learned song in zebra finches and raise questions concerning the neural sites and cellular mechanisms that mediate this feedback control.

Animal Communication↗

PubMed1992

Changes in stereotyped central motor patterns controlling vocalization are induced by peripheral nerve injury.

Adult male zebra finches (Taeniopygia guttata), as closed-ended learners, normally crystallize their songs at 90 days of age, and the song remains fixed throughout life (Price, 1979). We show that injuring the tracheosyringeal nerve(s) (each of which innervates the ipsilateral half of the syrinx, the avian vocal organ) results in a short-term deficit in the syllables forming adult male song; this deficit disappears after ts nerve regeneration. However, when adult males were followed for a period of several weeks after unilateral tracheosyringeal nerve injury, long-term changes occurred in the temporal patterning of song. Syllables were deleted, remaining portions of the song were linked, and new syllables were added. Syllables with call-like morphology were less likely to be deleted from and more likely to be added to the song. Deletions were most often contiguous chunks of syllables. Changes in the temporal patterning of song occurred during specific periods following nerve injury, were completed within 100 days after nerve transection, and were not dependent upon regeneration of the ts nerve. The resulting newly formed song patterns were stable, remaining unchanged up to 1 year later. The ability of adult male zebra finches to make specific types of changes to crystallized song indicates that some form of vocal plasticity remains even after song learning is completed, though this plasticity may be restricted to a subset of song characteristics. The limitations on the types of changes that are possible may reflect how song is centrally organized.

Animal Communication↗

PubMed1980

Photoacoustics in life sciences.

Photoacoustic (PA) measurements provide, by the very nature of the PA effect, the possibility to obtain information on the optical and thermal properties of samples. In addition they can yield information on the enthalpy changes and characteristic times involved in photo-induced processes as the acoustic signal is proportional to the hear produced following the absorption of the modulated excitation. In the study of optical properties the relative insensitivity to scattered light of the PA signal makes such measurement an attractive way to measure biological samples in vivo, or, at least, without the need to isolate the absorbing compounds. The dependence of the PA signal on the thermal properties of the sample is particularly useful when heterogeneous samples are studied. As a photocalorimetric method the technique shows considerable promise in the study of photo-bioenergetics, especially photosynthesis. Only in special cases can analytical applications of the PA method compete with fluorescence measurements for detection, and with increasingly sophisticated optical transmission and reflectance techniques (for identification).. However, the PA method may find important uses in fundamental research and in applied areas such as biomedicine and agricultural biochemistry.

Calorimetry↗

PubMed1990

Relations between depressed mood and vocal parameters before, during and after sleep deprivation: a circadian rhythm study.

The mechanism underlying improvement after total sleep deprivation (TSD) was studied in 14 major depressed patients. The suggestions that (1) circadian processes and/or (2) dimensions of arousal may play a role in the response to TSD were investigated. Diurnal variation of depressed mood and of mood- and arousal-related vocal parameters was studied in relation to the effect of TSD on depressed mood and vocal parameters. During 3 baseline days, during TSD and 2 days after TSD vocal parameters and depressed mood were assessed 6 and 3 times daily respectively. The mean fundamental frequency (frequency of vocal fold vibration, F0) (presumably reflecting aspects of arousal) as well as the range of the F0 (proposed to reflect sadness) showed a clear circadian pattern with a peak at about 4.00 p.m. TSD affected the circadian organization of the mean F0 and advanced the peak of the curve. After one night of subsequent sleep this effect disappeared. In addition, improvement after TSD coincided with an increase of the mean F0. The diurnal variation of mood before TSD predicted the mood response to TSD, whereas diurnal variation of vocal parameters did not. Moreover, circadian changes in vocal parameters were not related to changes in depressed mood. These findings suggest that the diurnal variations in mood and vocal parameters are regulated by different mechanisms. Data support the presumption that circadian as well as arousal processes are involved in the mood response to TSD. Circadian changes in vocal parameters due to TSD are not likely to reflect changes in the biological clock.

Adult↗

PubMed1992

Why and how should we study infant cry?

The study of the acoustics of infants' vocalizations has important implications for the study of infant development and for clinical prediction. We suggest procedures that enhance the probability of discriminating among sub-glottal, periglottal, and supraglottal sites of pathology, With these procedures, then, it should become possible to contribute to diagnosis and therefore to treatment.

Acoustics↗

PubMed1987

Sex difference in ultrasound distress call by rat pups.

Ontogenic changes in ultrasound production by isolated rat pups were compared in male and female pups of litters of various sex compositions. In both sexes, the peak of emission of sound around 50 kHz was on days 4-5, while 40 kHz sound production peaked on days 6-7. By days 4-5 each pulse is an inverted V-shape with frequencies between 40 and 55 kHz. At the peak of sound production, pulses with a slight downsweep from 40-45 kHz were prominent, and in the preweaning period, pulses of a relatively stable frequency of 35-40 kHz were emitted. There was a general tendency for sound pulses of female pups to be of short duration compared with those of male pups. The ontogenic changes in the ultrasonic distress call are less variable throughout all female pups of litters consisting of 2, 4, 6 or 8 female pups in a litter of 8. In contrast to this, it was found that male pups emit ultrasound more vigorously than female pups from days 2-3 to days 12-13 when male and female pups coexisted in the same litter. The activity of sound production of male pups which had no female littermates was similar to that of female pups. These findings suggest that the interaction of some kind between male and female pups produces the sex differences in the ultrasonic distress calls as early as several days after birth in the rat.

Aging↗

PubMed1989

Microcomputer-aided studies of cry jitter uttered by newborn children based upon high-resolution analysis of fundamental frequencies.

The metrological and computational problems of detecting very weak variations in the frequencies of the fundamental tone are discussed from a signal processing point of view. An appropriate computer method of high-resolution analysis of the fundamental frequency is proposed. When applying high-resolution fundamental frequency analysis to cry signals, a jitter was found to exist in the fundamental frequency curve of both healthy babies and those suffering from cerebral disorders. A method is given to separate the jitter from the fundamental frequency curve. The separated jitter curve depends on the degree of slope of the fundamental frequency curve and shows differences between healthy and ill babies. For an objective evaluation of the jitter abnormities, an integral parameter--the so-called cry-jitter index--is proposed.

Algorithms↗