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PubMedDate not supplied

[The combined activities of the temporal cortical area and hippocampus in man during the localization of a moving sound image].

In patients with epileptic lesions in the cortex and mediobasal structures of the brain, studies have been made on the perception of spatial position of sound images during dichotic stimulation. It was established that the extreme interval which is necessary for formation of sensation of the moving sound image increases during right-side lesions of the temporal cortex. During left-side lesion of the temporal lobe, more diffuse disturbances in the trajectory of image movement (from the right and left) are observed, whereas right-side lesions result in disturbances of movement only at the opposite side of the latter. Cortical lesions and those in the mediobasal parts of the temporal lobe are accompanied by identical gradient of disturbances in the trajectory of sound image movement and short-term imprinting of succession of signals which differ with respect to their spatial position. Maximum disturbances are observed during lesions in the cortical and mediobasal parts of the temporal lobe, whereas only cortical lesions or only hippocampal lesions result in less significant disturbances. It is suggested that combined activity of the auditory cortex and hippocamp is necessary for localization of a sound source.

Acoustic Stimulation↗
PubMed1990

Timing and character of reciprocal temporomandibular joint sounds in an asymptomatic orthodontic sample.

The timing and character of opening and closing temporomandibular joint sounds were evaluated in a sample of 33 asymptomatic subjects with reciprocal clicking. Using stereophonic headphones and videotape recordings, three consecutive reciprocal sounds were recorded and analyzed. The timing of the three consecutive opening and closing sounds was consistent in the majority of subjects, and occurred generally on late opening and middle to late closing. When the timing, character (frequency, amplitude, and duration), and wave patterns were evaluated, a notable amount of variation was observed in the overall sample. This suggested a variety of intra-articular reasons for the reciprocal sounds in this particular sample of subjects.

Adolescent↗
PubMed1990

Heart sound simulation: how useful for critical care nurses?

Forty critical care nurses participated in a 2-hour teaching program using a heart sound simulator to increase skill in recognition of heart sounds. Mean test scores increased 10 points from the pretest to the first posttest (t = 11.9, p = 0.0001), and this increase was maintained on the second posttest 3 weeks later. Medical intensive care unit and coronary care nurses scored higher than the other critical care nurses. There was a low correlation between recognition of sounds and years of critical care experience. The correlation between the subjects' self-rating of knowledge of heart sounds and their actual skills was also low. These findings suggest that a similar teaching program might be useful for critical care nurses.

Adult↗
PubMed1989

Feasibility of wing beat sound trap for the control of mosquito vectors.

Early observations suggested that the female sound was a possible cause of mating. Attempts had been made for introduction of female wing beat sound for removal male mosquitoes from the population for the control purpose. The traps emitted female wing beat sound, were set on black clothes as a swarm marker, could collect a large number of male Cx. tritaeniorhynchus in Japan. Those traps were later improved with introduction of two attractants, hamster and dry ice. Consequently, two systems were adopted for efficiency trapping of males and females. A cylinder trap with 350 Hz of wing beat frequency was introduced for male Cx. tritaeniorhynchus collection, while the cage trap with 530 Hz was for female collection. The traps were set every other days after sun set for three weeks in a paddy field. Although there was no decrease of population density, the reduction of parous rate was evident. For future effective control, it may suggest the need to distribute more wing beat sound traps to cover all larva breeding paddy field and near by blood sources. On the other hand, other control methods should be integrated.

Animals↗
PubMed1989

Use of a heart sound simulator in teaching cardiac auscultation.

The use of a heart sound simulator in teaching recognition of heart sounds was tested in 37 graduate students. Subjects were randomly divided into two groups; one group received both auditory and tactile cues and the other group received only auditory cues. Students were tested at three times: (1) before use of the simulator, (2) after a short teaching session using the simulator, and (3) 2 weeks later. Recognition of heart sounds increased significantly after the teaching session with the simulator, and this knowledge was retained. There was no difference in sound recognition between the two groups.

Adult↗
PubMed1986

Effects of sound on swarming male Psorophora columbiae.

Male Psorophora columbiae were shown to respond to sound during swarming. The responses consisted of abrupt changes in flight speed and direction. Tones with frequencies of 200 to 425 Hz were attractive to males over a distance of at least 1 m. Male mosquitoes responded better to tones with sine waveforms than they did either to square waveforms or triangular waveforms. Swarming males became accommodated and no longer responded to sounds presented for 5 seconds or longer. Based on observations of field populations of swarming Ps. columbiae, it appears that males use sound waves to locate females, but additional factors seem to be required for males to initiate the actual copulatory behavior. Also, males appear to use sound to maintain their position and spatial relationship within the swarm.

Animals↗
PubMedDate not supplied

[Method for the evaluation of flow rate from pulmonary sounds].

We recorded the lung sound and flow rate from six normal subjects (3 male and 3 female). Sound was picked up at the trachea with a sensitive microphone held in a small probe. Flow rate was measured at the mouth using a Fleisch No. 3 pneumotachograph. Subjects were made to breath for 15 s, with an increasing peak flow rate starting from apnoea to around 2 l.s-1. Both sound and flow rate were directly digitized (i.e. without temporary analogic recording) at a sampling rate of 5120 Hz. Sound and flow were then divided in 128-sample blocks. For each block, the frequency spectrum was computed using the fast Fourier transform. Frequency spectrum depends on the flow rate in many ways. We computed the following formula on each spectrum: D = K.Fmean/(1 + A/Amean) where K and A are constant, Fmean and Amean are respectively the mean frequency and the mean amplitude of the spectrum computed on a 128-sample block. D may be considered as an evaluation of the flow rate every 50 ms. Plotted versus the measured values of the flow rate, D showed a linear relationship. This feature can be used as an almost instantaneous evaluation of the flow rate, or it is possible to compute the mean of D over consecutive 128-sample blocks. This has lead us to calculate the mean of the flow rate over 100, 200, ..., 800 ms. Of course, the longer the time window, the better the correlation between computed flow and real value. The values obtained for this correlation varied between 0.79 and 0.94.

Female↗
PubMed1987

[The physiologic 3d heart sound in childhood. Determination in phonocardiography and assessment by auscultation].

The phonocardiographic characteristics of the IIIrd heart sound in children, accepted in the literature, are examined. In 231 out of 687 children with a normal heart, aged from hour 0 to 17 years, the IIIrd heart sound (HS) was phonocardiographically registered in the t and m1 frequency band. The findings on the frequency, sound frequency, sound duration, intervals II-III and T-III, and IIIrd HS amplitude related to the Ist and IInd HS amplitudes are compared with data in the literature. The audibility of the IIIrd HS increases with its low frequency equal or higher than 25 Hz, and its amplitude reaching or exceeding one-quarter of the preceding Ist HS and one-third of the preceding IInd HS.

Adolescent↗
PubMed1986

Binaural response organization within a frequency-band representation of the inferior colliculus: implications for sound localization.

The auditory system of the mustache bat (Pteronotus parnellii) contains a disproportionately large representation of a narrow frequency band, corresponding to the dominant, 60 kHz component of its echolocation signal. In the inferior colliculus (IC), the 60 kHz representation comprises an architectonically distinct region called the dorsoposterior division (DPD), which is accessible for detailed physiological study. We examined the topographic distribution of binaural responses within this one frequency-band representation of the inferior colliculus. We describe two primary results. First, neurons with different binaural response properties are spatially segregated into one of four binaural response-specific regions of the DPD: a large region of monaural (EO) responses; two regions containing neurons excited by sound from both ears (EE); and a region containing neurons excited by one ear and inhibited by the other (EI). Regions dominated by 60 kHz EI responses are also found in the lateral extremity of the IC, probably within the external nucleus. These results demonstrate functionally defined subdivisions in a single frequency-band representation of the IC. Moreover, they suggest that brain stem auditory projections to the DPD and/or intrinsic connections within the DPD are highly organized. Second, within the EI region of the DPD, there is a systematic shift in the sensitivity of EI multiunit responses to interaural intensity disparities (IIDs). Dorsally, EI neurons are suppressed only by relatively loud ipsilateral sounds, and there is a systematic decrease in the relative ipsilateral intensity required for suppression at more ventral recording sites. This result demonstrates that neurons sensitive to a sound localization cue are systematically organized within a frequency-band representation of the inferior colliculus. It has implications for the manner in which the location of a sound source is encoded within the primary auditory pathway.

Animals↗
PubMedDate not supplied

Recording esophageal heart sounds with a catheter-tip contact microphone.

The use of a catheter-tip microphone is described for the detection of heart sounds in the esophagus. The intensity and quality of the sounds differ from those detected on the precordium. Individual valve and breath sounds can be attenuated by choice of the location of the microphone in the esophagus. The acoustic shielding provided by the thorax allows presentation of heart sounds with little difficulty from acoustic feedback.

Animals↗
PubMed1978

Sound localization: value in localizing lesions of the auditory pathway.

Reports in the literature suggest that patients with otosclerosis, neural lesions such as acoustic neuroma, pontine lesions, and temporal lobe lesions may show abnormal sound localization ability. In the present experiment, 15 normal subjects and 22 patients with various auditory pathway lesions had sound localization testing using special apparatus. The results confirmed that patients with otosclerosis were unable to localize low frequency sounds. Those with temporal lobe lesions made judgments not significantly different from normal subjects. Patients with unilateral sensorineural deafness made errors localizing high frequency sounds. Those with acoustic neuromas made greater errors than those without, but the difference between these two groups just failed to reach statistical significance. The number of cases was however small, and further studies are in progress to attempt to define numerical criteria to assist clinical decisions with regard to the selection of patients for invasive investigations such as oil cisternogram.

Deafness↗
PubMedDate not supplied

Reappraisal of some problems concerning the genesis of heart sounds.

This paper sums up for clinical purposes the recent data and some of the authors' own observations concerning the genesis and variability of heart sounds. The importance of some factors in the "cardio-hemo-vasculo-thoracic" complex where the heart sounds are produced and transmitted, is especially emphasized; such are: acceleration and decelaration of the blood, rapidly variable shape and compliance of the cardiovascular container, turbulence phenomena, atrial and ventricular contraction and relaxation, closure and opening of cardiac valves. The role of some physiological or pathological changes in myocardial contractility and compliance in over- or underdamping of intracardiac vibrations generating heart sounds, is also analysed. Some examples of alteration of the 4th, 1st, 2nd and 3rd sound in the 3rd degree A--V block, nodal rhythm, short P--R, LBBB, aortic atherosclerosis, myocardial infarction, are presented.

Adult↗
PubMed1983

[Sound spectrographic studies in the diagnosis of dysfunctions of mechanical heart valve prostheses (Björk-Shiley prostheses)].

A newly developed real-time sound spectroanalyzer was found to be capable of diagnosing malfunction of prosthetic heart valves (Björk-Shiley prostheses). Sound spectroanalysis was carried out 430 times on 257 patients with a prosthetic heart valve. The valvular click of prosthetic heart valves shows a typical sound spectroanalysis pattern in real time, with a high-frequency peak which diminishes beyond 25 kHz. Thrombosis of the prosthetic heart valve causes loss of the valvular click and reduction in the intensity of the high-frequency components, as shown in 4 patients. Thus the sound spectroanalysis appears to be a noninvasive technique which may allow early diagnosis of a thrombosed prosthetic heart valve. We believe this method to be superior to phonocardiography and echocardiography.

Aortic Valve↗
PubMed1981

Prophylaxis of adhesions with low frequency sound.

Despite a multitude of ingenious ideas, a review of the literature has revealed no consistently acceptable results concerning adhesion prophylaxis. While pharmacologic avenues are far from exhausted, presently, there is no acceptable regimen. A double blind experimental study was performed with 130 Sprague-Dawley rats to determine the effect of high intensity low frequency sound on postoperative adhesion formation. Standard cecal crush was used to induce adhesions in rats which were then divided into four groups. The control rats exhibited 83 per cent adhesion formation while the rats in the other groups displayed an incidence inversely related to the duration of low frequency sound exposure. A reduction to 23 per cent adhesion formation was achieved in the group exposed to infrasound for 12 days. The controlled application of low frequency sound generates micromotion of the abdominal organs; moving surfaces do not lend themselves to spanning fiber formation. Studies disclaim significant side-effects of low frequency sound in man nor were any detected in the rats used in this study.

Animals↗
PubMed1981

[Response of medial geniculate body responses to the velocity of simulated sound source movement in the cat].

36 neurons (39%) of the anaesthetized cat medical geniculate body responded to simulated motion of the sound source (with angular velocity of 30 to 180 degrees/sec) selectivity with a certain speed of firing rate changing specific for each neuron during action of the signal. Selective response to a certain velocity of the sound motion occurred in 55% of neurons of the dorsal portion and in 27% of the ventral portion of the medial geniculate body. Response of these neurons reflected the whole range of experimental velocities. 75% of neurons revealed most obvious responses to the sound motion velocity of 30--90%/sec. The selective response to a certain velocity of the sound motion seems to depend on the direction of motion.

Animals↗
PubMed1981

[Heart sounds and heart murmurs in progressive muscular dystrophy of Duchenne type (author's transl)].

Phonocardiographic and echocardiographic investigation was performed in patients with progressive muscular dystrophy of Duchenne type (PMD). The clinical materials consisted of 90 patients with PMD (aged 8 to 21 yrs, a mean of 14.5), and 90 normal subjects (aged 6 to 19 yrs, a mean of 11.7). The patients with PMD were classified into 8 stages from the mildest, S(1), to the severest, S(8), according to Swinyard-Deaver' criteria. In the 90 normal subjects the diminished first heart sound was noted in 12 cases (13.3%), presystolic murmurs in 4 cases (4.4%), and diastolic rumbles in 9 cases (10%), whereas, in the patients with PMD the diminished first heart sound was noted in 47 cases (52.2%), presystolic murmurs in 41 cases (45.6%), and diastolic rumbles in 44 cases (48.9%). There was a significant difference in the incidence of the above-mentioned three phonocardiographic findings between the PMD patients and the normal subjects. But there was no significant difference in the incidence of a systolic click between these two groups. The incidence of the diminished first heart sound increased with the progress of Swinyard-Deaver' classification. A presystolic murmur was observed with the highest incidence in the stage of S(8). The incidence of a rumble was also augmented with increasing severity of the disorder from the stages of S(1) to S(7), but decreased in S(8). Another attenpt was made to relate the phonocardiographic findings to those of the echocardiogram. In the cases with anterior mitral leaflet fluttering, there were diastolic rumble in 69% whereas 16.7% of the patients without anterior mitral leaflet fluttering had diastolic rumbles. In two-dimensional echocardiography, the anterior and posterior mitral leaflets looked like pennants fluttering in the wind. All these observations positively indicate that anterior mitral leaflet fluttering was closely associated with the genesis of rumbles. Consequently, it can be concluded that the diminished first heart sound, presystolic murmurs and diastolic rumbles might be useful clinical signs in the assessment of the myocardial involvement in PMD.

Adolescent↗
PubMed1980

Real-time sound spectroanalysis for diagnosis of malfunctioning prosthetic valves.

A newly developed real-time sound spectroanalyzer was found to be capable of diagnosing malfunction of prosthetic heart valves. Sound spectroanalysis is believed to be superior to other methods such as phonocardiography and echocardiography. This system, developed in our institute, allows display on a cathode ray oscilloscope of five different modes of the valvular click, including the sound spectrograph and section pattern. Analysis of the section pattern allows measurement of the high-frequency components of the valvular click, which is normalized so as to be applicable to a click of any intensity. This parameter is called normalized maximal frequency (NMF). Sound spectroanalyses were carried out 228 times on 127 patients having a prosthetic heart valve. NMF values of normally functioning valves differed characteristically according to the type of valve, but did not change during the postoperative time course. Three of seven patients who had cerebral embolism showed significantly lower NMF values than normal, as did all four patients whose valve had become thrombosed.

Atrial Fibrillation↗
PubMed1995

Multimedia presentation of lung sounds as a learning aid for medical students.

New educational technologies might help to compensate for the decrease in time and emphasis dedicated to physical examination in medical training. This may, in particular, be applicable for improving the skills in auscultation of the chest. We investigated whether a multimedia presentation of acoustic and graphic characteristics of lung sounds could improve the learning of pulmonary auscultation by medical students, in comparison with conventional teaching methods. We studied 48 medical students without clinical experience, who had received conventional formal teaching on chest examination. Chest auscultation skills were evaluated using an inaccuracy score for the student's auscultation report on three patients, selected according to a standardized procedure. After a baseline evaluation, 27 students in groups of 5-10, participated in a multimedia seminar on lung sounds during which digitized lung sounds were played and the corresponding time-expanded waveform and frequency spectrum were commented on and displayed on a computer. The remaining 21 students received conventional bedside training, acting as control group. The following week, all the students underwent a second evaluation of chest auscultation skills. No differences in the inaccuracy score were observed between the two groups in the preliminary test. However, in the second postintervention assessment, the inaccuracy score of the students who had followed the seminar (11.2 +/- 1.3 points) was significantly lower than that of the controls (16.6 +/- 1.6 points). The answers to a feedback questionnaire confirmed that the great majority of the students found the association of the acoustic signals with their visual image to be useful for learning and understanding lung sounds.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗