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At least 1,549 records · Page 86Linked to original sources
PubMed2006

Assessing children's heart sounds at a distance with digital recordings.

OBJECTIVE: The objective of this study was to assess whether computer-stored digital sound recordings can be used to distinguish innocent from pathologic systolic murmurs. METHODS: Recordings of 55 children aged 1 month to 19 years were made remotely with the use of a digital stethoscope and were e-mailed to a computer in our center for later assessment. Eight-second recordings were made by a physician in 2 to 4 locations on the chest. Three cardiologists who were blinded to the diagnosis reviewed the recordings independently using stethophones to assess the splitting of the second heart sound and whether murmurs were innocent or pathologic. Diagnoses were confirmed with echocardiography. RESULTS: Seventeen children had innocent murmurs and 38 had pathologic murmurs. For the 3 cardiologists, sensitivity was 0.87 to 1.0, specificity was 0.82 to 0.88, negative predictive value was 0.75 to 1.0, and positive predictive value was 0.93 to 0.95. Assessment of splitting of second heart sound was highly accurate. CONCLUSIONS: Digital recordings of children's heart sounds allow reliable differentiation between innocent and pathologic murmurs. Use of this technology may allow remote diagnosis of childhood murmurs and avoid the expense and stress of travel to pediatric cardiology centers for some children. Cardiologists who use recordings should assess their diagnostic accuracy before clinical application.

Adolescent↗
PubMed1993

Individual differences in preference for environmental sounds.

25 typical environmental sounds were presented to 936 Japanese high school students in a written questionnaire to measure their preferences for these sounds. Sex-related, personality-related, and regional differences among preferences were observed for kind of sound. On the other hand, self-rated frequency of hearing each sound in daily life was related to the subjects' residential environment and sex.

Adolescent↗
PubMed1995

Acceptable levels of tonal and broad-band repetitive and continuous sounds during the performance of nonauditory tasks.

Three groups of 24 subjects were exposed to a 1000-Hz tone or broad band noise in a sound chamber. During the exposures subjects were engaged in an easy reaction time test or a difficult grammatical reasoning test. For each exposure and work subjects adjusted the noise to a tolerance level defined by its interference with task performance. During the simple reaction-time task significantly higher sound-pressure levels were accepted than during the reasoning test. At the tonal exposure, much lower levels were accepted than during the exposure to broad-band noise. For continuous sound exposures much higher levels were accepted than for noncontinuous exposures. For tonal exposures the difference was approximately 5 dB, for the broad-band exposures approximately 9 dB. In a separate study the effects of the noncontinuity of the noise and pauses were analysed. The raised annoying effect of the noncontinuous noise was not more affected by the noncontinuity of the noise periods than by the noncontinuity of the pauses. The results imply that the annoying reactions to the sound will be increased for repetitive noise and that the reaction is highly influenced by the over-all noncontinuity of the exposure.

Acoustic Stimulation↗
PubMed1984

Fetal heart rate response to a controlled sound stimulus after propranolol administration to the mother.

The fetal heart rate response to a controlled sound stimulus was recorded in 36 pregnant women before and after a maternal peroral dose of either 80 mg propranolol, or placebo. The sound stimulation was repeated 60 minutes, 120 minutes and 180 minutes after the drug administration. The fetal heart rate response to sound was significantly depressed by this moderate dose of propranolol. The sound stimulation method is found to reflect sensitively the immediate influence of propranolol on the fetus.

Acoustic Stimulation↗
PubMed1984

Fetal heart rate response to sound stimulation after pethidine injection in the mother.

A method for electronic supervision of the human fetus based upon controlled sound stimulation of the fetus and the fetal heart rate response was used to evaluate the effect of pethidine on the fetus. Half an hour after intramuscular injection of 100 mg pethidine in the mother, the fetal heart rate response to sound stimulation was already depressed in 10 out of 20 cases. A general depression of the heart rate response to sound was found 2 and 3 hours after the injection. The fetal heart rate response to sound stimulation seems to constitute a sensitive record of pethidine's influence.

Female↗
PubMedDate not supplied

Responses of squirrel monkey vestibular neurons to audio-frequency sound and head vibration.

A study was made of the response of peripheral vestibular neurons in the squirrel monkey to head vibration and air-borne sound in the frequency range from 50-4 00 Hz. Responses were measured in terms of the phase locking of discharge and changes in firing rate. The lowest phase-locking thresholds for vibration were -70 to -80 dB re 1 g, and median values in the most sensitive frequency range (200-400 Hz) were -20 to -40 dB re 1 g; the minimum and median thresholds for sound were 76 and 120-130 dB SPL, respectively. Rate-change thresholds were 10-30 dB above phase-locking thresholds. The squirrel monkey sacculus has no special sensitivity to vibration in comparison with the other vestibular end-organs; the median phase-locking threshold to sound of saccular neurons exceeded 100 dB SPL. Irregularly discharging neurons are more sensitive than regularly discharging units. Evidence is presented that the response to intense sound involves a hair-cell mechanism.

Acoustic Stimulation↗
PubMed1980

Calculation of noise dose from time distribution of sound levels.

The noise from ten different sites in a machine factory was measured and cumulative time distributions of the sound pressure were constructed. From these distributions it is possible to calculate the energy mean level, the equivalent sound level as well as the average sound pressure level. Calculations based on knowledge of the times during which only a few sound pressure levels are exceeded give values deviating systematically from the exact value. Because of the systematic nature of the deviations corrections can be made for them. The accuracy of this method is relatively high.

Acoustics↗
PubMed1983

Sound levels recorded within the symphony orchestra and risk criteria for hearing loss.

Investigations into noise-induced hearing loss should consist of two parts: a mapping of the sound environment and a charting of hearing loss. This paper is the first part of such an investigation: a mapping of sound levels and sound spectra within the symphony orchestra. It was found that 'heavy' symphonic music exceeds the permitted dose for industrial noise equivalent to 85 dB(A) for a full working week. The permitted noise dose is reached for 'heavy' music after a working time of 10 hours per week in 'exposed' positions, such as in front of trumpets, and after 25 hours in 'normal' positions. A simple method to estimate the 'noise' exposure in equivalent sound level for combination of different sorts of music has been developed.

Hearing Loss, Noise-Induced↗
PubMed1988

Assessment of sound in the ear canal caused by movement of the jaw relative to the skull.

To assess whether or not the reduction of threshold to bone-conducted sound on occlusion of the ears (the occlusion effect) is due to compression of the auditory meatus by the jaw, measurements of movement of the skull and mandible and sound in the ear canal are reported from four subjects. The change in bone-conducted sound in the ear canal was also measured when the mandible was moved out and in (presenting more or less of the mandible to compress the auditory meatus) and when vibration was applied directly to the mandible. Sound pressure increased when the jaw was moved out and when vibration was applied to the mandible.

Air Pressure↗
PubMed1997

Cutaneous senses for detection and localization of environmental sound sources: a review and tutorial.

A review and tutorial on the potential use of the skin for sound localization are presented. Some basic physical and psychophysical properties are reviewed; special properties and phantom perceptions associated with cutaneous stimulation are presented; experiments by Békésy, Gescheider, Frost, Richardson and Weisenberger on different instrumentation for/and results on localization of sound sources with skin stimulation are analysed. The best results have been obtained using intensity differences between two vibrators. Sound source localization precision approaching that of the auditory sense in quiet surroundings has been obtained, particularly when free head movements are allowed. Significant results have also been obtained with temporal differences, provided the natural sound delay between the ears is increased to fit the coding characteristics of the skin. As yet, no portable equipment has been designed and tested in realistic environments.

Auditory Perception↗
PubMed1990

Continuous adventitious lung sounds.

Recent research has increased the still limited understanding about the generation of continuous adventitious lung sounds. These sounds all have a definite pitch, such as in stridor and wheezing. With the use of waveform analysis, one can examine more closely the relationship between what is heard and the pathophysiology causing the sound. Clinical examples are given to show the utility and limitations of current lung sounds analysis techniques.

Acoustics↗
PubMed1990

A portable system for the spectral analysis of cough sounds in asthma.

A practical and portable method is described to analyze the sound spectra of coughs. The system is based upon a personal computer and simultaneously collects the sounds of cough heard both at the mouth and through the chest wall together with the airflow at the mouth produced during the cough. Subsequent analysis produce spectrographs of the cough sound linked to the corresponding airflow. The system will be used initially to examine the effects of exercise on the sound of cough in asthma. Further study of cough spectra in this way may be useful in the management of asthma either diagnostically or in the assessment of therapeutic interventions.

Asthma↗
PubMed2000

Evidence on the efficacy of insert earphone and sound field VRA with young infants.

Visual reinforcement audiometry (VRA) with insert-earphone stimulus delivery provides a means of obtaining early ear-specific information on the auditory status of infants. The aim of this study was to investigate the efficacy of VRA in young infants, and to compare the use of sound field and insert-earphone stimulus presentation. VRA was performed on 41 normally developing infants aged between 20 and 42 weeks. Infants were tested in the sound field (n=22) and with insert earphones (n=19). Results showed significantly more minimum response levels (MRLs) obtained with sound field testing, and with older children. Nevertheless, in the insert-earphone group, 36% of those aged 32 weeks or more gave two or more MRLs, and 25% of the infants aged 25 weeks or less gave one or more MRLs. This study provides data from developmentally normal infants which confirms the efficacy of insert-earphones as well as sound field VRA with 32-42-week-olds, with reasonable expectation of success. The data in this study also suggest that VRA could be usefully employed for younger infants aged approximately 20-26 weeks where information, although less easily obtained, may be of particular value to early diagnosis and habilitation.

Audiometry↗
PubMed1980

Sound localization and early binaural experience in the deaf.

The sound localisation ability of four groups of severely deaf children is reported. It was found that those children who had some early experience of binaurally presented sound were likely to retain the ability to localise sounds, although if such experience was via binaural hearing aids, it was not certain to lead to retention of the ability. Children with early experience of sound which lacked interaural cues were likely to have lost the ability to localise, whether the experience was due to a severe asymmetric deafness or early single aid provision. The parallel with the loss of stereopsis in children with an uncorrected strabismus is drawn.

Age Factors↗
PubMed1994

In vitro sound spectral analysis of prosthetic heart valves by mock circulatory system.

A comparative study was made of the sounds produced by normal prosthetic valves (St. Jude Medical, Bjork-Shiley, polymer) with those produced by the same valves but having simulated thrombosis at the stent, hinge, or strut. Comparisons of the closing sound were made for the power frequency spectra associated with individual valves. We used periodogram approach to obtain the spectral characteristics of the valve prostheses. The closing sound of the abnormal mechanical valves displayed lower apparent peak frequency. But the abnormal polymer valve produced higher apparent peak frequency. The results showed that frequency spectra gave information pertinent to the simulated malfunction. Sound spectral analysis is believed to be a simple and a good diagnostic tool for detection of prosthetic valve malfunction. Also it seemed to be superior to other methods such as phonocardiography and echocardiography.

Fourier Analysis↗
PubMed2005

Coherence of the irrelevant-sound effect: individual profiles of short-term memory and susceptibility to task-irrelevant materials.

We examined individual and developmental differences in the disruptive effects of irrelevant sounds on serial recall of printed lists. In Experiment 1, we examined adults (N = 205) receiving eight-item lists to be recalled. Although their susceptibility to disruption of recall by irrelevant sounds was only slightly related to memory span, regression analyses documented highly reliable individual differences in this susceptibility across speech and tone distractors, even with variance from span level removed. In Experiment 2, we examined adults (n = 64) and 8-year-old children (n = 63) receiving lists of a length equal to a predetermined span and one item shorter (span-1). We again found significant relationships between measures of span and susceptibility to irrelevant sounds, although in only two of the measures. We conclude that some of the cognitive processes helpful in performing a span task may not be beneficial in the presence of irrelevant sounds.

Adult↗
PubMed2000

Cross-modal selective attention: on the difficulty of ignoring sounds at the locus of visual attention.

In three experiments, we investigated whether the ease with which distracting sounds can be ignored depends on their distance from fixation and from attended visual events. In the first experiment, participants shadowed an auditory stream of words presented behind their heads, while simultaneously fixating visual lip-read information consistent with the relevant auditory stream, or meaningless "chewing" lip movements. An irrelevant auditory stream of words, which participants had to ignore, was presented either from the same side as the fixated visual stream or from the opposite side. Selective shadowing was less accurate in the former condition, implying that distracting sounds are harder to ignore when fixated. Furthermore, the impairment when fixating toward distractor sounds was greater when speaking lips were fixated than when chewing lips were fixated, suggesting that people find it particularly difficult to ignore sounds at locations that are actively attended for visual lipreading rather than merely passively fixated. Experiments 2 and 3 tested whether these results are specific to cross-modal links in speech perception by replacing the visual lip movements with a rapidly changing stream of meaningless visual shapes. The auditory task was again shadowing, but the active visual task was now monitoring for a specific visual shape at one location. A decrement in shadowing was again observed when participants passively fixated toward the irrelevant auditory stream. This decrement was larger when participants performed a difficult active visual task there versus fixating, but not for a less demanding visual task versus fixation. The implications for cross-modal links in spatial attention are discussed.

Adolescent↗
PubMed2005

Do we hear size or sound? Balls dropped on plates.

The aim of this study is to examine whether it is possible to recover directly the size of an object from the sound of an impact. Specifically, the study is designed to investigate whether listeners can tell the size of a ball from the sound when it is dropped on plates of different diameters (on one, two, or three plates in Experiments 1, 2, and 3, respectively). In this paradigm, most of the sound produced is from the plate rather than the ball. Listeners were told neither how many different balls or plates were used nor the materials of the balls and plates. Although listeners provided reasonable ball size estimates, their judgments were influenced by the size of the plate: Balls were judged to be larger when dropped on larger plates. Moreover, listeners were generally unable to recognize either ball and plate materials or the number of plates used in Experiments 2 and 3. Finally, various acoustic properties of the sounds are shown to be correlated with listeners' judgments.

Auditory Perception↗