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At least 19 recordsLinked to original sources
PubMed1976

[Sound spectrographic investigations of heart sounds and murmurs and of the sounds produced by artificial valves (author's transl)].

The normal heart sounds, murmurs, opening and closing sounds of aortic and mitral valve prostheses were recorded on a tape in order to obtain the highest frequencies which were recordable on the chest wall. Sections of these tapes were analyzed in terms of contour sonagrams. For this purpose six groups were formed and investigated: group I comprised persons without cardiovascular diseases, group II patients with mitral valve failure, group III patients with aortic valve failure, group IV patients with congenital heart disease, group V patients with Starr-Edwards aortic valve prostheses (model 1260) and group VI patients with various mitral valve prostheses. In each of these groups the highest recordable frequencies were measured. The peak frequencies varied widely in regard to frequency range in a comparison of the six groups. The maximum was reached at about 8000 c.p.s. in the case of the sounds of prosthetic valves. Furthermore, sound level examinations of the normal first and second heart sounds, as well as of the opening and closing sounds of the aortic valve prostheses were performed. The highest sound level of all of these sounds was found to lie within the low frequency range of 40 to 100 c.p.s. The results of both the measurements of the peak frequencies and of the maximal sound level were discussed on the basis of the presently accepted theories on the mechanism of heart sounds and murmurs.

Aortic Valve↗
PubMed1992

[Wave form of intrabronchial spark sound on the chest wall and sound transmission in the lung-thoracic system].

A spark sound was generated in the canine bronchus and sound waves were observed on the surface (skin) and on each layer (pectoralis major muscle, intercostal muscle and parietal pleura) of the chest wall. The sound wave observed on the surface of the chest wall was 5-10 ms in duration, 400-500 Hz in dominant frequency and 0.6-1.2 ms in the duration of the initial deflection. Reverse dispersion of the waves, i.e., the later components of the wave having longer periods, was also recognized. These characteristics of the wave were similar to those of time-expanded wave-form of crackle, i.e., discontinuous adventitious lung sounds, in clinical cases. Both the spark sound and the sound wave observed on the visceral pleura were of short duration, being 0.7 ms and 1 ms, respectively. therefore, the main component of the sound wave observed on the chest surface was considered to reflect the physical properties of the chest wall itself. The analysis of place relationship within the chest wall suggested that transmission of the sound across the chest occurred not as a surface wave but as a longitudinal wave, therewith traversing the chest wall directly from the sound source. The arrival time of the sound was well correlated with the distance between the sound source and the positions of the pick-ups on the surface of the chest wall. Assuming that the medium between the source and the lung and in the chest wall were 71.5 and 29.6 m/sec, respectively. Further studies will be necessary to clarify the theory of the sound transmission through the living tissue as a viscoelastic body.

Animals↗
PubMed1990

[Study on occlusal sounds in children. 2. Fast Fourier Transform (FFT) analysis on the occlusal sounds].

The purpose of this study was to evaluate the Fast Fourie Transform (FFT) analysis of the occlusal sounds generated by tooth tapping which may apply in assisting in the functional diagnosis of occlusion in children. The fifteen subjects examined were divided into three groups: the first group with deciduous dentition, the second with mixed dentition and the third with permanent dentition. Occlusal sounds generated by tooth tapping at the rate of 76 times per minute were obtained with a micro-electronic condenser microphone placed on the infra-orbital region. For the time wave, the wave pattern of the occlusal sound was classified into two groups: 1) Impact sound, 2) Slide sound, and the ratio of appearance was examined. For the spectrum, three parameters were chosen for the measuring points such as 1) frequency range, 2) peak frequency, 3) strength of the peak frequency. The results obtained in the present study were summarized as follows: 1) Occlusal sounds in the deciduous dentition, the appearance of sliding sound was noticed in over 50% of the cases while on the permanent dentition, the sliding sound was dominant. 2) The power spectrum of the occlusal sound showed generally two or three peaks. 3) The range of frequency was recognized to be extended on the sliding sound when compared with the impact sound.

Child↗
PubMed1977

[Contoursonagraphic analysis of heart sound phenomena and sounds produced by various heart valve prostheses].

The normal heart sounds, murmurs, opening and closing sounds of aortic and mitral valve prostheses were recorded on a tape and analyzed in terms of contour sonagrams in order to obtain the highest frequencies which were recordable on the chest wall. The peak frequencies showed a broad range, the maximum beeing reached at about 8000 c.p.s. in the case of the sounds of prosthetic valves. Furthermore, sound level examinations of the normal first and second heart sound, as well as of the opening and closing sounds of the aortic valve prostheses were performed. The highest sound level of all of these sounds was found to lie within the low frequency range of 40 to 100 c.p.s.

Aortic Valve Insufficiency↗
PubMed1975

First heart sound and ejection sounds. Echocardiographic and phonocardiographic correlation with valvular events.

To provide additional information on the relation of valvular events to the principal components of the first heart sound (s1), combined echocardiograms and phonocardiograms were recorded in 49 subjects, chosen because of audible splitting of S1 or a combination of S1 and an ejection sound. The subjects included 14 normal persons, 16 patients with a variety of predominantly right-sided heart conditions, 7 with mitral stenosis, 3 with pulmonary stenosis and 9 with aortic valve disease or systemic hypertension. A precise relation was found between completion of closure of the atrioventricular (A-V) valves manifested in the echocardiogram and the high-frequency components of S1 (M1 and T1). The average time from the Q wave of the electrocardiogram to M1 was 0.06 plus or minus 0.003 second and the Q-T1 interval was 0.09 plus or minus 0.002 second. In mitral stenosis the Q-M1 interval was delayed to 0.10 plus or minus 0.005 second, resulting in some instances in reversed splitting of S1. In pulmonary stenosis, the ejection sound occurred 0.10 plus or minus 0.003 second from the Q wave. In 7 of the 16 patients with various right-sided abnormalities, but without valvular stenosis, an ejection sound of pulmonary origin occurred 0.18 plus or minus 0.012 second from the Q wave. In the nine patients with aortic valve disease or systemic hypertension, the time from the Q wave to the aortic ejection sound was 0.13 plus or minus 0.004 second. With only two exceptions the ejection sounds of aortic and plumonary origin coincided exactly with achievement of a fully opened position of the respective semilunar valve. Our findings support the postulate that M1, T1 and the ejection sounds occur in association with closing or opening of valves with consequent sudden deceleration or acceleration of a column of blood that, in turn, results in vibrations of the cardiohemic system and audible sounds.

Adolescent↗
PubMed1990

Interaction between tracheal sound and flow rate: a comparison of some different flow evaluations from lung sounds.

We simultaneously recorded tracheal sound and air flow from nine normal subjects (seven males and two females). Sound was picked up at the supra sternal notch with an air-coupled sensitive microphone held in a small airtight probe. Flow was measured at the mouth using a pneumotachograph Fleisch n degrees 2. Both sound and flow were directly digitized at a sampling rate of 5120 Hz and then divided in 128-sample blocks. For each sound block the frequency spectrum was computed using the fast Fourier transform. In order to evaluate instantaneous flow-rate from tracheal sounds we investigated eight methods divided in two groups of four. In the first group (i.e., reference curves methods), we assumed that a relationship existed between sound and flow and was thus reflected by the variations of certain parameters. We chose to use simple straightforward relationships, already known and published. We tested four different parameters. During a calibration phase, we built for each parameter P a reference curve representing the variations of P versus flow and being specific to each subject. Then, an unknown flow was evaluated in calculating P on a 128-sample block, and the reference curve gave the corresponding flow. In the second group, we made a hierarchial clustering analysis of sound spectra for revealing the frequency modifications, induced by the flow. We tested two kinds of spectra as well as two ways of associating a flow to a given cluster. This led us to four other methods for calculating the flow. All the eight methods but one gave a mean uncertainty in the measure of flow of about 15%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Acoustical analysis of occlusal sound--transfer functions of oral cavities and characteristics of waveform of occlusal sound].

The purpose of this study is to clarify the acoustical characteristics of the occlusal sound. An FFT analyzer was used to analyze the transfer functions of the oral cavities. The characteristics of the waveform of the occlusal sound were investigated by the time-frequency analysis. The results obtained were as follows: (1) There were three peaks in the low frequency area of the transfer functions of the oral cavities. The duration of the impulse responses of the oral cavities had a wide variation among the individuals. (2) The waveform of the occlusal sound by air-conduction was proved to consist of two components. One was the teeth collision sound produced by the collision of the teeth in the oral cavity and emitted directly out from the oral cavity. The other was the reverberation considered to be formed mainly by the resonance system in the oral cavity. (3) By the time-frequency analysis, the teeth collision sound could be distinguished clearly from the reverberation; the former was recognized as the component where the energy existed up to the high frequency area, while the latter was recognized as the component where the energy existed only in the low frequency area. (4) It was suggested that the teeth collision sound, after separating from the reverberation, should be analyzed for the purpose of obtaining further information about the functional condition of the occlusion from the occlusal sound.

Adult↗
PubMed1992

Infants' perception of illusions in sound localization: reaching to sounds in the dark.

Sixteen infants each at 4, 6, and 8 months of age were tested for reaching to sounding toys in the dark under two auditory illusion conditions: the Haas-effect, which creates the illusion of a single lateralized sound based on an interaural intensity difference (the toy was visible and invisible under some test conditions); and the midline illusion, which creates the illusion of a single sound at midline due to an absence of any interaural time or intensity differences (invisible toy condition only). No-sound control trials indicated the level of spontaneous reaching in the dark. Results indicate that by 4 months infants perceive both the Haas-effect and midline illusions. The ability to reach both for invisible and visible sounding objects in the dark was well developed by 4 months of age, although developmental changes in aspects of reaching behavior were observed and, at all ages, object contact was most frequent when visual localization cues accompanied sound localization cues. The incidence of spontaneous reaching in the dark was low and did not vary with age. Theoretical and methodological implications of this research are discussed.

Acoustic Stimulation↗
PubMed1991

[Analysis of transmission of continuous adventitious lung sounds in asthmatic patients--a comparison with continuous sounds due to bronchial stenosis].

We studied the acoustic features of continuous adventitious lung sounds in asthmatic patients, and analyzed the characteristics of transmission by comparing the continuous sounds in asthmatic patients with those due to bronchial stenosis. The results were as follows. 1) Continuous adventitious lung sounds in patients with bronchial stenosis confirmed by bronchoscopy were well transmitted to the neck over the trachea. Therefore, it was demonstrated that continuous adventitious lung sounds generated in the lung are able to be transmitted to the tracheal region. 2) Continuous adventitious lung sounds in asthmatic patients were divided into monophonic tones and polyphonic tones, according to sound spectrographic findings. From the results of the coherence analysis, the monophonic tones were considered to be generated in the right or left lung, and were well transmitted to the neck over the trachea. The origin of the polyphonic tones was unknown, but they were also relatively well transmitted to the neck over the trachea. It was confirmed that the tracheal region is a very important location for auscultating and monitoring asthmatic patients.

Adult↗
PubMed1990

[Study on occlusal sounds in children. (1). Influences of the velocity of tooth tapping on the occlusal sound].

The purpose of this study was to evaluate the influence of the maximum velocity of the mouth closing phase on the occlusal sound. Six subjects examined were divided into two groups (children and young adults). Occlusal sounds generated by the tooth tapping were obtained with in microelectronic condenser microphone placed on infra-orbital and external auditory canal. Three parameters were used for the measuring points such as 1) maximum velocity of the closing phase, 2) maximum amplitude of the occlusal sound, 3) duration of the occlusal sound. The results obtained in the present study were as follows: 1) The waveform of occlusal sounds obtained from infra-orbital showed more clearly than that obtained from the external auditory canal. 2) With increasing velocity, both the values of maximum amplitude and duration showed a tendency to increase in both groups. 3) The prolonging of the duration was apparent in the children. The results obtained in the study suggest that the analysis of the occlusal sounds generated by tooth tapping can apply to aid in the functional diagnosis of occlusion in children.

Adult↗
PubMed1976

[Variations in the loudness of a brief sound compared to another brief sound as a function of the duration of both sounds].

Loudness equalizations between two short 2500 Hz tones (15 to 120 ms, about 50 dB SPL) were made. One tone, either the first or the second one, was twice as long as the other. The intensity level differences between tones of the same loudness were calculated. Results show that the relations between duration and loudness of the tones differ for different subjects. Nevertheless the calculated differences diminished with subject experience. Subject evaluations in accordance with the intensity levels of tones, i.e. independently of the duration, were quite often obtained even for the pairs 15 ms-30 ms.

Acoustic Stimulation↗
PubMed1979

Suggested threshold sound pressure levels for frequency-modulated (warble) tones in the sound field.

The problems inherent in using frequency-specific stimuli in the sound field to determine threshold sensitivity are reviewed, including a discussion of some of the specific problems encountered when introducing pure tones, narrow bands of noise, and frequency-modulated (FM) tones. The results of two experiments are reported. In Experiment I, the relationship between pure tones and frequency-modulated tones is developed under earphones in an anechoic chamber, and in two sound-isolated auditory test rooms (not anechoic). Experiment I resulted in the development of a reference threshold sound pressure level for frequency-modulated signals in the sound field. In Experiment II the reference level was applied to a clinical test facility and evaluated with a group of hearing-impaired individuals. The results suggest that the sound-field reference levels accurately reflect monaural threshold under earphones, when the earphone is calibrated to the ANSI, 1969 standard, and the sound field is calibrated to the suggested standard.

Acoustic Stimulation↗
PubMed1976

A test of the practical value of estimating breath sound intensity. Breath sounds related to measured ventilatory function.

Each of four examiners performed standardized physical examinations on a group of patients who had just undergone tests of ventilatory function. The intensity of breath sounds heard with deep inspiration was graded on a rating scale of 0 to 4; the grades in six areas of the chest were added to give a total score, with possible values ranging from 0 to 24. Correlation of breath-sound scores with percentage of predicted forced expiratory volume in one second (FEV1) was significant at the 1 percent level for all of the examiners. Differences between the examiners in their assessment of breath sounds were not statistically significant. Grading the loudness of breath sounds was a poor screening test for mild ventilatory abnormality, but normal breath sounds nearly excluded the possibility of severe reduction in the FEV1. Definitely reduced breath-sound intensity was strong evidence for the presence of obstructive pulmonary disease.

Adult↗
PubMed1991

Sound field measurement tutorial. Working Group on Sound Field Calibration of the Committee on Audiologic Evaluation American Speech-Language-Hearing Association.

Although there are no standards or guidelines for sound field testing, it is recognized that such testing is an integral part of audiologic evaluation. This paper has reviewed some of the problems in sound field testing, as well as possible solutions to those problems. This review may be summarized as follows: 1. The environment in which sound field testing is conducted is an integral part of the test procedure; thus, the ambient noise and reverberation characteristics of the test room must be known. The test room must have ambient noise levels below the level at which the test signals will occur. 2. The listener must be seated so that the SPL of the test signal is known at that listener's pinna. Thus, care must be taken to exclude anything between the ear of the listener and the loudspeaker, and the height of the loudspeaker must be appropriate for the listener. (Note: If the loudspeakers are raised or lowered, it may be necessary to recalibrate.) The near/far field and direct/reverberant field boundaries should be identified and the listener positioned between those two boundaries. 3. The acoustic properties of the test signal must be defined clearly. An FM signal is best for assessing threshold of hearing. The examiner should measure the SPL and verify the spectral characteristics of the signal. The frequency of calibration measurements should be identical to that used for earphones, generally once every 3 months. Finally, it is important to understand the potential interaction between the test environment, the signal, and the listener when testing in the sound field. If the problems are understood and compensations are made it should be possible to obtain reliable and useful auditory information in the sound field.

Acoustics↗
PubMed1990

[A quantitative study of TMJ sounds. 1. A systematization on frequency analysis of clicking sounds].

TMJ clicking sound is a sign worth noticing as prodromal symptoms of TMJ dysfunction. Therefore, a solution of its characteristics is an important matter to grasp the diagnosis of stomatognathic function and progress of the disease. We try to systematize the procedure from picking-up TMJ sound to convertion of frequency and then investigate picking-up method and the measurement apparatus, because we need a quantitation of acoustical components of clicking sound to examine the influence of hearing ability due to TMJ dysfunction. The following were obtained: 1. Low frequency noise is reduced by using headgear with microphone located in a external ear. 2. We pick up continuous 30 TMJ sounds three times in separate days. The waveforms of each set are approximately similar. 3. Each peak frequency and pattern of power spectrum examined three times show high correspondence. 4. The range of maximum peak frequencies in all subjects are from 0 to 0.8 KHz.

Auscultation↗
PubMed1991

Isovolumic relaxation sound: a new class of added heart sound?

An early diastolic sound in a patient with apical left ventricular disease is reported. Pulsed Doppler echocardiography showed blood flow within the left ventricular cavity during the isovolumic relaxation period whose peak flow velocity was synchronous with the onset of this diastolic sound. Because it occurred before filling started it could not have been either a third or fourth heart sound. It must thus represent a distinct and apparently unrecognised class of diastolic sound.

Aged↗
PubMedDate not supplied

[Determination of the location of sound sources by dogs exposed to dichotic sounds].

Lateralization thresholds for dichotically presented sounds were measured in dogs by avoidance technique. The animals were trained to lift the left paw when the sound was presented at left, and the right one when it occurred at right. The sound lateralization was achieved by varying interaural time and intensity level differences. Click trains and tonal pulses of 0.3, 1.0 and 5.0 khz frequencies were used as sound stimuli. The threshold for click trains was found to be equal 55--60 mcs for temporal cue and 1.5--1.8 dB for intensity differences. The lateralization threshold turns out to depend on frequency of tonal pulses. Intensity difference thresholds drop with increasing frequency whereas the temporal ones rise. The lateralization for frequencies above 1.5 khz could not be achieved.

Animals↗
PubMed1992

[Heart sounds--a mathematical transformation of blood pressure? On the origin of heart sounds].

Two main theories exist concerning the origin of the heart sounds. The first proposes that rapid pressure fluctuations cause the cardiac valve leaflets to vibrate and produce the sound. The second theory suggests that sudden pressure perturbations cause the entire cardiohemic mass to vibrate as a whole. In 35 patients (26 men and 9 women, aged 18 to 73) with various heart diseases microtransducer catheters (Millar) were used to simultaneously record aortic pressures and aortic internal phonocardiograms in order to determine if they had a common mode of origin and propagation. The propagation velocities of the first heart sound and the foot of the aortic pressure pulse were found to be similar, 5.24 +/- 0.61 m/s and 5.97 +/- 1.87 m/s respectively (+/- SE). It was possible to derive facsimiles of the aortic internal phonocardiogram by double differentiation of the corresponding aortic pressure pulse and conversely to derive the pressure pulse by double integration of the phonocardiogram. These data support the concept that the low-frequency pressure variations produced by the entire cardiohemic mass, which predominate in the aortic pressure pulse waveforms, are generated and propagated in the same manner as the high-frequency pressure variations, which are the first and second heart sounds.

Adolescent↗