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PubMed1984

On categorizing aphasic speech errors.

Acoustic studies of voice-onset-time in aphasics' speech suggest that fluent aphasics' errors are misselected phonemic targets whereas nonfluent aphasics' errors are of articulatory origin. However, we must be cautious when extrapolating a theory from only one measure of articulation. In this experiment, I examined utterances produced by five fluent aphasics, five nonfluent aphasics and two controls. First, the voice-onset-time findings were replicated. Second, I examined the duration of vowels preceding word-final stop consonants as an index of the consonant's voicing category. The pattern of voice-onset-times produced did not predict the pattern of vowel durations. Thus, voice-onset-time cannot be used to characterize more generally the output of the speaker.

Adult↗
PubMed1989

Stop consonant production in isolated and repeated syllables in Parkinson's disease.

To determine if Parkinson's disease (PD) patients have increasing difficulty as speech tasks become longer or more complex, the timing and accuracy of isolated syllables and repeated sequences of syllables were studied. Acoustic measures of PD patient's syllables were similarly impaired relative to normal controls for both isolated and repeated syllable sequences. Listeners' identification scores were equally high for both types of productions. Unlike previous studies of other types of movements in PD, speech accuracy and timing does not deteriorate as items become longer or more complex.

Aged↗
PubMed1994

Asymmetric performances in binaural localization of sound in space.

Twenty right-handers and 20 left-handers were tested on a sound localization task. Broadband noise was presented from either the left or right hemifield. Localization accuracy was significantly greater (P = 0.002) when sounds emanated from the left hemifield thereby suggesting a paramount role played by the right hemisphere. Correcting for front-rear reversals, attributable to impoverished spectral cues and/or faulty processing of such cues, rendered differences in error scores linked to hemifield nonsignificant. The data were interpreted to mean that the special contribution of the right hemisphere to this task was its greater fidelity in processing spectral cues. No differences in localization proficiency between right- and left-handers were observed.

Adult↗
PubMed1990

Startle-inducing acoustic stimuli evoke ultrasonic vocalization in the rat.

The present study demonstrates that acoustic stimuli which induce a startle response (ASR) also evoke ultrasonic vocalization in the rat. Sound recordings were done on three consecutive days of testing during sessions of 20 acoustic stimuli each and on the following day for three minutes following 5 acoustic stimuli (nonstimulus condition). Startle-inducing stimuli evoked continuous ultrasonic calling which was maintained throughout testing. Immediately following each acoustic stimulus, however, vocalization was interrupted by a period of silence (gap). The mean duration of sounds was reduced and the interpulse interval tended to increase during acoustic stimulation as compared to the nonstimulus condition. It is concluded that startle-eliciting stimuli induce a state of fear in the rat and that the acoustic-startle-elicited ultrasonic vocalization may provide a novel model in the study of anxiety.

Animals↗
PubMed1991

Twenty-two kHz alarm cries to presentation of a predator, by laboratory rats living in visible burrow systems.

When a cat was presented to groups of 3 male and 2 female laboratory rats in the open area of a visible burrow system, the rats retreated to the burrow system and showed high levels of 18-24 kHz ultrasonic cries during the cat presentation and for 30 min following removal of the cat. Latency to make ultrasonic vocalizations, durations of these vocalizations, and duration in the burrow systems were all strikingly and reliably different during and after cat exposure in comparison to similar periods with a control (stuffed cat toy) stimulus. However, when individual rats were exposed to a cat in an open area of similar size, ultrasonic cry production was minimal. Also rats exposed individually to a cat in an apparatus providing an escape chamber similarly showed no ultrasonic cries, indicating that concealment per se is not a sufficient condition for their appearance. These results suggest that the production of ultrasonic vocalizations during and after exposure to a predator is greatly facilitated by the presence of familiar conspecifics, and may serve as alarm cries. While the alarm cry hypothesis also suggests a possible function for 18-24 kHz ultrasounds in the context of copulation and intraspecies aggression, the sonographic and functional relationships among the cries emitted in these different situations remain to be analyzed.

Animals↗
PubMed1992

Ultrasonic vocalization of laboratory rats in response to handling and touch.

The goal of the study was to investigate the ultrasonic vocalization induced in freely behaving, naive rats by gentle touch with a human hand. Thirty-nine rats were tested in an unfamiliar experimental cage with repeatable hand touch. Vocalization appeared with an average latency of 4.6 +/- 5.0 s (SD). The nape of the neck was the most effective area, and after a couple of stimuli applied, 66.7% of rats emitted 21-32 kHz ultrasonic vocalization. It consisted of multiple series of long calls, about 70% of which exceeded 300 ms. The responses quickly habituated from session to session to extinction. Significantly more rats housed in single cages vocalized ultrasonically than animals housed in community cages. The long latencies of the vocalization, their appearance in multiple series to a single touch, and quick habituation to the stimuli indicate that 22 kHz ultrasonic vocalization of rats reflects a distress caused by a potential danger to the animal and it does not necessarily reflect physical discomfort or pain. This vocalization may, therefore, play an adaptive role in increasing chances of survival by conveying information about potential threats to other conspecifics.

Animals↗
PubMed1993

Analysis of 22 kHz ultrasonic vocalization in laboratory rats: long and short calls.

There is a remarkable variation in the length of single ultrasonic calls emitted by adult rats. The duration of calls is likely to convey information for conspecifics. The goal of the present study was to analyze 22 kHz calls emitted by naive laboratory rats in response to contact with the human hand and to measure their acoustic features, with a particular emphasis on call duration. Repeated hand touch applied to the nape of the neck of rats induced ultrasonic calls, 97.4% of which were within the range of 20-29 kHz and 2.6% of which were within 44-67 kHz. Distribution of duration of 6765 calls revealed two subpopulations of 22 kHz calls: 20-300 ms calls with its peak at 150 ms and calls above 310 ms with highest values at approximately 500-600 ms without a clear peak. These two call populations were referred to as short and long calls, respectively. The short and the long vocalizations contained 80% and 100% of calls within the range of the 22 kHz frequency, respectively. The findings indicated that, in the situation studied, the 22 kHz vocalization of adult rats consists of two distinguishable subpopulation of calls: short and long with the boundary between them at 300 ms.

Animal Communication↗
PubMed1993

Sound levels in rooms housing laboratory animals: an uncontrolled daily variable.

High sound levels are known to have adverse effects on the behaviour and physiology of laboratory animals, yet their acoustic environment is rarely monitored. In particular, high-frequency sounds that are above the limit of human hearing, but are well within the limits of many laboratory species (i.e., ultrasounds), are usually ignored. In this study, the acoustic environment of laboratory animals was investigated in a variety of different animal facilities. Sound pressure levels (dB SPL) were monitored for periods up to 24 h over two frequency ranges: a relatively low range (0.01-12.5 kHz), and a high range (12.5-70 kHz). While background sound levels in undisturbed situations were generally low (i.e., below 50 dB SPL), marked increases in sound levels often occurred during the working day, producing characteristic daily variations in the sound profile. Peak SPLs commonly reached values of 80-95 dB in the low-frequency range and 50-75 dB in the higher range. In most cases, sound levels were low over weekends. The results suggested that human activities were a very important source of sound in most animal facilities. In a few situations (e.g., rabbits, marmosets, dogs), the animals themselves provided a significant contribution to the acoustic environment. It is clear that the acoustic environment of laboratory animals is a daily variable that is usually uncontrolled and that may have important implications for behavioural and physiological experiments and for animal welfare.

Animal Welfare↗
PubMed1994

Dissociation of androgen-dependent sociosexual behaviors in response to castration in Long-Evans rats.

Copulatory behavior and associated social behaviors such as ultrasonic vocalizations and scent marking are reduced in frequency following castration and are restored by exogenous administration of androgens. In the present study, we report the behavior of a subgroup of male Long-Evans rats in which there was a dissociation between the responses of androgen-dependent behaviors to castration. Five weeks after castration, 52% of the males tested (13 of 25) had higher 50 kHz vocalization frequencies than during precastration tests. This group continued to emit vocalizations after castration and actually increased their number of vocalizations over postcastration tests (pretest: 34.5 +/- 4.8 to week 15: 62.8 +/- 10.9/10 min test). The remaining males (n = 12) exhibited a decline in vocalizations (pretest: 29.7 +/- 5.1 to week 15: 6.5 +/- 2.7) that we typically observe in our laboratory. Both groups showed the expected decline in scent-marking frequency over the postcastration tests and were impaired in performance of copulatory behavior. Seminal vesicle and adrenal gland weights did not differ between the two groups. The 25 males were of the same genetic strain as previous animals in our laboratory except that they were born and raised in a different location prior to shipment to our laboratory. Androgens, therefore, may be only one of the possible influences mediating ultrasonic vocalizations.

Androgens↗
PubMed1986

Effects of lung volume and airflow on the frequency spectrum of vesicular lung sounds.

UNLABELLED: The purpose of this study was to determine whether the vesicular lung sound frequency spectrum is affected by changes in lung volume and airflow. Nine healthy young nonsmokers were studied. The dependent variables were the points that divide the power spectrum of the vesicular lung sound into quarters (1st, 2nd and 3rd quartiles (Q1, Q2 and Q3]. Recording sites were the right upper anterior (RUL) and lower posterior (RLL) chest wall. Lung sounds were high-pass filtered at 100 Hz. To evaluate the effect of volume, lung sounds were recorded during an inspiratory vital capacity (VC) maneuver at near constant airflow rates. The spectral parameters were determined at each sixth of the VC. To assess the effects of airflow, 5 of the subjects breathed from resting lung volume at peak inspiratory airflows of between 1 and 3.0 L/sec for a total of 16 breaths each and the frequency parameters of the lung sounds occurring during peak inspiratory airflows were determined. RESULTS: Volume effects: only at the RUL was there a small but significant decrease in all three parameters with increasing lung volume. Airflow effects: all parameters were independent of airflow except for a weakly positive relationship (r = 0.285, P less than 0.05) for Q3 at the RUL location. Individually, there were weakly significant trends in three of the five subjects. These data suggest that the frequency composition of the vesicular lung sound in groups of healthy adults is not systematically affected by changes in lung volume or airflow.

Adult↗
PubMed1985

Temporal speech characteristics associated with anterior left hemisphere cortical and subcortical lesions: a preliminary case study report.

There is disagreement in the literature regarding the characteristics of cortical and subcortical forms of aphasia. M. L. Albert, H. Goodglass, N. A. Helm, A. B. Rubens, and M. P. Alexander (Clinical Aspects of Dysphasia, Vienna/New York: Springer-Verlag, 1980) state that the two are indistinguishable. The opposing view has been presented by M. A. Naeser, M. P. Alexander, N. Helm-Estabrook, H. L. Levine, S. A. Laughlin, and N. Geschwind (Archives of Neurology, 39, 1982) and A. R. Damasio, H. Damasio, M. Rizzo, N. Varney, and F. Gersh (Archives of Neurology, 39, 15-20, 1982), who suggest that subcortical aphasias are not adequately described by the classic, cortical aphasia descriptions. In this study the temporal speech characteristics of a neurologically normal individual, an aphasic patient with anterior cortical and subcortical lesion locus, and a second aphasic patient, whose lesion was limited to anterior subcortical structures, were studied utilizing acoustic analysis of isolated word and phrase productions. The results of this investigation showed individually unique temporal patterns in the speech of each of the subjects studied. While the results must be interpreted conservatively due to the small number of cases described, they do provide tentative support for the Naeser et al. (1982) and Damasio et al. (1982) position. Furthermore, the results demonstrate the potential value of combining sensitive radiographic and acoustic measures in future studies that seek to compare cortical and subcortical forms of aphasia.

Aphasia↗
PubMed1986

Disturbed coarticulation in apraxia of speech: acoustic evidence.

The results of a recent perceptual study (W. Ziegler & D. von Cramon, 1985, Anticipatory coarticulation in a patient with apraxia of speech. Brain and Language 26, 117-130) provided evidence for disturbed coarticulation in verbal apraxia. Further support for this finding is now provided by acoustic analyses. Formant frequencies and LP reflection coefficients were chosen to assess anticipatory vowel-to-vowel coarticulation and vowel anticipation in stop consonants, respectively. These parameters revealed a lack of coarticulatory cohesion in the speech of a patient suffering from verbal apraxia, explainable by a consistent delay in the initiation of anticipatory vowel gestures. The findings are discussed with respect to prosodic features and to theoretical and clinical concepts of verbal apraxia.

Adult↗
PubMed1987

The neurological substrates for prosodic aspects of speech.

The ability to comprehend and produce the stress contrast between noun compounds and noun phrases (e.g., greenhouse vs. green house) was examined for 8 nonfluent aphasics, 7 fluent aphasics, 7 right hemisphere damaged (RHD) patients, and 22 normal controls. The aphasics performed worse than normal controls on the comprehension task, and the RHD group performed as well as normals. The ability to produce stress contrasts was tested with a sentence-reading task; acoustic measurements revealed that no nonfluent aphasic used pitch to distinguish noun compounds from phrases, but two used duration. All but one of the RHD patients and all but one of the normals produced pitch and/or duration cues. These results suggest that linguistic prosody is processed by the left hemisphere and that with brain damage the ability to produce pitch and duration cues may be dissociated at the lexical level.

Aged↗