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At least 721 records · Page 40Linked to original sources
PubMed1997

Genetic and developmental influences on infant mouse ultrasonic calling. I. A diallel analysis of the calls of 3-day olds.

Ultrasonic calls produced by young mice reliably elicit investigation and retrieval by adults. While there are large individual differences in the characteristics of these calls, little work has been done to partition that variation. We completed a 4 x 4 diallel cross and Hayman analyses on several characteristics of these cries. The major result was the detection of directional dominance toward a higher rate of calling, longer calls, and calls of lower overall frequency with a greater bandwidth. Within the context of biometrical genetic theory, we conclude that calls with such characteristics may have important fitness value. Extending this idea, we propose that within the population sampled for this study (the animals of the four inbred strains and 12 F1 hybrid groups), the calls most effectively eliciting investigation and retrieval would be calls with the average hybrid values of the diallel cross.

Animals↗
PubMed2004

A simple computer-based measurement and analysis system of pulmonary auscultation sounds.

Listening to various lung sounds has proven to be an important diagnostic tool for detecting and monitoring certain types of lung diseases. In this study a computer-based system has been designed for easy measurement and analysis of lung sound using the software package DasyLAB. The designed system presents the following features: it is able to digitally record the lung sounds which are captured with an electronic stethoscope plugged to a sound card on a portable computer, display the lung sound waveform for auscultation sites, record the lung sound into the ASCII format, acoustically reproduce the lung sound, edit and print the sound waveforms, display its time-expanded waveform, compute the Fast Fourier Transform (FFT), and display the power spectrum and spectrogram.

Algorithms↗
PubMed2004

The selectivity of neurons in the auditory zone of the mouse midbrain to the direction of movement of a spectral notch in wide-band noise.

A series of noise signals was synthesized with spectral notches whose central frequencies moved regularly along the frequency range (from low frequencies to high and from high frequencies to low), imitating movement of the sound source in the vertical plane. The spike responses of neurons in the inferior colliculus of the mouse (Mus musculus) to noise signals changed as the spectral notch moved relative to the excitatory and inhibitory areas of the receptive fields of the neurons and depended on the notch width. Disinhibition reactions in the inhibitory zones were more marked when a frequency notch in the inhibitory zone was followed by a frequency notch in the excitatory part of the response. It is suggested that the selectivity of neurons to the direction of movement of the spectral notch in a noise signal is based on the interaction of the excitatory and inhibitory inputs. The overall set of neuron responses can provide information on the movement of the sound source in acoustic space.

Acoustic Stimulation↗
PubMed2002

[Reliability, trainability and stability of auditory discrimination performance in 2 computer-assisted assessment and training methods].

OBJECTIVES: The present study focuses on the possibilities and effects of training dyslexic children in tone and phoneme discrimination tasks. METHODS: A computer program was developed to train dyslexic children to discriminate between tone and speech stimuli. The correlation between auditory discrimination and reading and orthography performance was then tested in a preliminary study of n = 63 children. In a prospective study 44 children were assigned to one of three paralyzed groups: tone training, phoneme training or a control group. Upon completion of the initial diagnostics for all groups, the two training groups received four weeks of discrimination training, after which all three groups were immediately re-tested for the first time. Parallel thereto all children underwent specific training in reading and orthography at their school. Six months later all were re-tested a second time. RESULTS: Both test methods showed a high reliability (rn = .94; .95). Significant correlations between auditory discrimination and reading and orthography performance were confirmed. Auditory discrimination was significantly trainable. Specific training effects, as well as independent developmental effects were found. While the training effects of phoneme discrimination were stable over six months, those of tone discrimination were not. CONCLUSION: The central auditory discrimination between tone and phoneme stimuli can be trained successfully in dyslexic children and might also affect their reading and orthography performance.

Child↗
PubMed2003

A comparison of the contrast effects in sound localization in the horizontal and vertical planes.

The effect of a background sound on the auditory localization of a single sound source was examined. Nine loudspeakers were arranged crosswise in the horizontal and the median vertical plane. They ranged from -20 degrees to +20 degrees, with the center loudspeaker at 0 degree azimuth and elevation. Using vertical and horizontal centimeter scales, listeners verbally estimated the position of a 500-ms broadband noise stimulus being presented at the same time as a 2 s background sound, emitted by one of the four outer loudspeakers. When the background sound consisted of continuous broadband noise, listeners consistently shifted the apparent target positions away from the background sound locations. This auditory contrast effect, which is consistent with earlier findings, equally occurred in both planes. But when the background sound was changed to a pulse train of noise bursts, the contrast effect decreased in the horizontal plane and increased in the vertical plane. This discrepancy might be due to general differences in the processing of interaural and spectral localization information.

Adult↗
PubMed2000

When a "wheeze" is not a wheeze: acoustic analysis of breath sounds in infants.

Epidemiological studies indicate that the prevalence of "wheeze" is very high in early childhood. However, it is clear that parents and clinicians frequently use the term "wheeze" for a range of audible respiratory noises. The commonest audible sounds originating from the lower airways in infancy are ruttles, which differ from classical wheeze in that the sound is much lower in pitch, with a continuous rattling quality and lacking any musical features. The aim of this study was to clearly differentiate wheeze and ruttles objectively using acoustic analysis. Lung sounds were recorded in 15 infants, seven with wheeze and eight with ruttles, using a small sensitive piezoelectric accelerometer, and information relating to the respiratory cycle was obtained using inductive plethysmography. The acoustic signals were analysed using a fast fourier transformation technique (Respiratory Acoustics Laboratory Environment programme). The acoustic properties of the two noises were shown to be quite distinct, the classical wheeze being characterized by a sinusoidal waveform with one or more distinct peaks in the power spectrum display; the ruttle is represented by an irregular nonsinusoidal waveform with diffuse peaks in the power spectrum and with increased sound intensity at a frequency of <600 Hz. It is important for clinicians and epidemiologists to recognize that there are distinct types of audible respiratory noise in early life with characteristic acoustic properties.

Fourier Analysis↗
PubMed1992

Speech before and after treatment with bridges on osseointegrated implants in the edentulous upper jaw.

Speech may be affected by the transition from complete dentures to fixed prosthesis on osseointegrated implants (OIB). If so, is there any correlation between interdental spaces (open or closed) in the prosthodontic construction and deteriorated speech? 21 individuals advocated for maxillary OIB were randomised so that one half of the group got constructions with wide interdental spaces and the other half with minimised interdental spaces. All patients were examined audiologically and their speech was individually tape-recorded before and after treatment. Perceptual, acoustic, model and audiological analyses were made. Approximately 60% of the patients were judged to have indistinct speech after the treatment. The s-sound was perceptually and acoustically distorted. 67% of the patients suffered from hearing defects. No correlation between interdental spaces (open or closed) and deteriorated speech could be found. It is supposed, that hearing plays a part in the effort to adjust speech to a new maxillary OIB, and thus reduced hearing can enhance speech difficulties.

Adult↗
PubMed2002

Difference in anxiety and sensitization of the acoustic startle response between the two inbred mouse strains BALB/cAN and DBA/2N.

The inbred mouse strain BALB has been proposed to be an animal model for pathological anxiety. BALB exhibits a stronger acoustic startle response (ASR) than the 'less emotional' inbred strain DBA. Four experiments were conducted to determine whether this strong ASR is due to a higher anxiety level and/or to greater sensitization in BALB than in DBA, with the following results: (1) The ASR to the very first startle stimulus was found to be much stronger in BALB than in DBA, and freezing behavior evoked by startle stimuli was more pronounced in BALB than in DBA. These findings indicate a higher level of anxiety in this strain. (2) ASR amplitudes of BALB initially rose much higher during consecutive startle stimuli and remained at a high level much longer than in DBA. Thereafter, ASR amplitude dropped more slowly and to a lesser degree than in DBA. Startle amplitudes decreased similarly in both strains (strong exponential decrease) only when a low sound pressure level (SPL) was used which elicited approximately the same low ASR in both strains. These results can only be explained by increased sensitization in BALB. (3) The slope of the i/o-function, which represents the relation between sensory input and motor output, was steeper in BALB than in DBA. As it has been shown recently, sensitization increases the slope of the startle i/o-function indicating increased sensitization in BALB. It is discussed, however, whether anxiety also contributes to this effect. (4) Footshocks increased the ASR much less in BALB than in DBA, again showing increased sensitization in BALB. Both a higher level of anxiety and greater sensitization therefore determined the greater strength of the ASR in BALB than in DBA.

Acoustic Stimulation↗
PubMed1997

The effect of talker variability on word recognition in preschool children.

In a series of experiments, the authors investigated the effects of talker variability on children's word recognition. In Experiment 1, when stimuli were presented in the clear, 3- and 5-year-olds were less accurate at identifying words spoken by multiple talkers than those spoken by a single talker when the multiple-talker list was presented first. In Experiment 2, when words were presented in noise, 3-, 4-, and 5-year-olds again performed worse in the multiple-talker condition than in the single-talker condition, this time regardless of order; processing multiple talkers became easier with age. Experiment 3 showed that both children and adults were slower to repeat words from multiple-talker than those from single-talker lists. More important, children (but not adults) matched acoustic properties of the stimuli (specifically, duration). These results provide important new information about the development of talker normalization in speech perception and spoken word recognition.

Adult↗
PubMed1997

Mothers' and fathers' singing to infants.

Mothers and fathers sang a song of their choice, once to their infant and once as if to their infant (simulated). The pitch of songs was higher and the tempo slower for infant-directed than for simulated versions. Listeners varying in child-care experience, musical background, and cultural origin reliably identified which of the two versions was infant-directed (Experiment 1). Identification accuracy was enhanced by musical training, knowledge of the singers' language and culture, and by greater pitch and tempo differences between versions. Other adult listeners who rated the singer's emotional engagement assigned significantly higher ratings to infant-directed than to simulated versions (Experiment 2). Differences in pitch and tempo between both versions predicted emotional engagement ratings. Finally, rating differences between infant-directed and simulated versions were highly correlated with identification accuracy.

Adolescent↗
PubMed1999

Children's performance on pseudoword repetition depends on auditory trace quality: evidence from event-related potentials.

This study explored the relation between phonological short-term memory and auditory-sensory processing in 7-9-year-old children. Twenty-four participants performed a pseudoword repetition test. The mismatch-negativity (MMN) component of auditory event-related brain potentials was obtained from 9 participants with the highest and 9 participants with the lowest scores on the test. The MMN indexes short-term auditory-sensory memory, including auditory-sensory representations for speech. It was recorded to just perceptible /baga/-/baka/ bisyllabic and easily discriminable 1000/1100-Hz tone contrasts with interstimulus intervals of 350 and 2,000 ms. The high and low repeaters differed significantly in MMN amplitude to speech stimuli at the shorter interstimulus interval. Thus, the accuracy of auditory-sensory processing seems to affect phonological short-term representations in school-age children and therefore may play a role in vocabulary development.

Child↗
PubMed1996

Acoustic profiles in vocal emotion expression.

Professional actors' portrayals of 14 emotions varying in intensity and valence were presented to judges. The results on decoding replicate earlier findings on the ability of judges to infer vocally expressed emotions with much-better-than-chance accuracy, including consistently found differences in the recognizability of different emotions. A total of 224 portrayals were subjected to digital acoustic analysis to obtain profiles of vocal parameters for different emotions. The data suggest that vocal parameters not only index the degree of intensity typical for different emotions but also differentiate valence or quality aspects. The data are also used to test theoretical predictions on vocal patterning based on the component process model of emotion (K.R. Scherer, 1986). Although most hypotheses are supported, some need to be revised on the basis of the empirical evidence. Discriminant analysis and jackknifing show remarkably high hit rates and patterns of confusion that closely mirror those found for listener-judges.

Adult↗
PubMed1996

A nonverbal signal in voices of interview partners effectively predicts communication accommodation and social status perceptions.

Derivations from nonverbal communications accommodation theory are tested, and this knowledge is extended both theoretically and methodologically. Fast fourier transform and statistical analysis of a low-frequency nonverbal signal-in voices from 25 dyadic interviews between a talk show host and his guests revealed voice convergence between partners. Correlation coefficients from comparisons of partners' voice spectra and factor analysis of the correlation matrix showed that lower status partners accommodated their voices to higher status partners via the nonverbal signal. Student ratings of the social status of the same talk show host and guests were correlated with factor loadings, thereby providing convergent validity of the nonverbal signal as a predictor of social status perceptions and accommodation.

Dominance-Subordination↗
PubMed1984

More adaptation of speech by nonspeech.

Three experiments tested Samuel and Newport's (1979) hypothesis that the perceptual system sorts its input on the basis of its spectral quality (periodic vs. aperiodic). In Experiment 1, repeated presentation of a shaped white-noise segment (aperiodic) produced a labeling shift on a /ja-za/ continuum (primarily aperiodic); two periodic adaptors produced no effect, supporting Samuel and Newport's hypothesis. The second experiment replicated these results and showed that the nonspeech adaptor produced almost as much adaptation as the test series' endpoint /za). In addition, using several mixtures of periodic and aperiodic adaptors indicated that the aperiodic component dominates adaptation effects for /ja-za/. A final experiment, using a similarity rating task, confirmed that subjects group /za/ with unvoiced fricatives rather than with other voiced consonants. The results thus indicate that the perceptual system is sensitive to whether the input is primarily periodic or aperiodic, regardless of whether it is speech or nonspeech.

Adaptation, Physiological↗
PubMed1984

Auditory perception of breaking and bouncing events: a case study in ecological acoustics.

The mechanical events of bouncing and breaking are acoustically specified by single versus multiple damped quasi-periodic pulse patterns, with an initial noise burst in the case of breaking. Subjects show high accuracy in categorizing natural tokens of bouncing and breaking glass as well as tokens constructed by adjusting only the temporal patterns of components, leaving their spectral properties constant. Differences in average spectral frequency are, therefore, not necessary for perceiving this contrast, though differences in spectral consistency over successive pulses may be important. Initial noise corresponding to glass rupture appears unnecessary to categorize breaking and bouncing. The data indicate that higher order temporal properties of the acoustic signal provide information for the auditory perception of these events.

Adult↗
PubMed1986

Effect of experimentally induced stress on vocal parameters.

In a factorially designed experiment the factors Mode of Stress (cognitive vs. emotional) and Degree of Stress (low vs. high) were studied in their effect on phonatory and articulatory processes during speech production in groups of male and female students (factor Sex) selected to represent three types of personality (factor Coping Style: low anxiety, high anxiety, anxiety denying). Using digital speech analysis procedures, mean F0, F0 floor, formant location, and spectral energy distribution were extracted from the experimental speech samples. Although mean F0 did not covary with stress manipulation, F0 floor of high-anxious and anxiety-denying subjects increased with stress, probably due to physiologically based changes in muscle tension. For articulatory processes, as measured through formant location and spectral composition, significant changes were found for females. For anxiety-denying female subjects, precision of articulation increased under cognitive stress and decreased under emotional stress. The results are interpreted in terms of differential susceptibility to stress.

Anxiety↗
PubMed1988

Examination of perceptual reorganization for nonnative speech contrasts: Zulu click discrimination by English-speaking adults and infants.

The language environment modifies the speech perception abilities found in early development. In particular, adults have difficulty perceiving many nonnative contrasts that young infants discriminate. The underlying perceptual reorganization apparently occurs by 10-12 months. According to one view, it depends on experiential effects on psychoacoustic mechanisms. Alternatively, phonological development has been held responsible, with perception influenced by whether the nonnative sounds occur allophonically in the native language. We hypothesized that a phonemic process appears around 10-12 months that assimilates speech sounds to native categories whenever possible; otherwise, they are perceived in auditory or phonetic (articulatory) terms. We tested this with English-speaking listeners by using Zulu click contrasts. Adults discriminated the click contrasts; performance on the most difficult (80% correct) was not diminished even when the most obvious acoustic difference was eliminated. Infants showed good discrimination of the acoustically modified contrast even by 12-14 months. Together with earlier reports of developmental change in perception of nonnative contrasts, these findings support a phonological explanation of language-specific reorganization in speech perception.

Adult↗