Results for “Sound” — Page 5

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

[Sound reception in marine mammals depending on sound parameters and conduction pathways].

The interaction of complex sounds with the body tissues of Black Sea dolphin (Tursiops truncatus) was studied by the method of instrumental conditioned reflexes with food reinforcement. The thresholds of detecting underwater acoustic signals of different frequencies for dolphin and northern fur seal (Callorhinus ursinus) were measured as a function of pulse duration under conditions of full and partial (head above water) submergence of animals into water. It was found that sound conduction through dolphin tissues was more effective than that in a northern fur seal in a wide frequency range. Presumably, the process of sound propagation in dolphin is accompanied by changes in the amplitude-frequency structure of broad-band sounds. The temporal summation in dolphin hearing was observed at all frequencies under conditions of full and partial submergence, whereas in northern fur seal it was nearly absent at a frequency of 5 kHz under the conditions of head lifting above water.

Acoustic Stimulation↗

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↗

PubMed1989

Rapid assessment of sound-evoked olivocochlear feedback: suppression of compound action potentials by contralateral sound.

The compound action potential (CAP) measured at the round window of anesthetized cats in response to low-level tone pips can be significantly suppressed by addition of tones or noise to the opposite ear. This contralateral-sound suppression disappears upon transection of the olivocochlear bundle. The frequency and level dependence of the suppression phenomenon are well explained by known sound-evoked discharge properties of single olivocochlear neurons. Thus, the contralateral-sound suppression of cochlear CAP should prove useful as a rapid measure of the magnitude of the sound-evoked efferent feedback to the cochlea.

Animals↗

PubMed1994

Population responses to multifrequency sounds in the cat auditory cortex: one- and two-parameter families of sounds.

Population responses to multi-frequency sounds were recorded in primary auditory cortex of anesthetized cats. The sounds consisted of single-tone stimuli; two-tone stimuli; and nine-tone stimuli, with the tones evenly spaced on a linear frequency scale. The stimuli were presented through a sealed, calibrated sound delivery system. Single units, cluster activity (CA) and the short-time mean absolute value of the envelope of the neural signal (MABS) were recorded extracellularly from six microelectrodes simultaneously. The CA and MABS were interpreted as measures of the activity of large populations of neurons, in contrast with the single unit activity which is presumably recorded from single neurons. The responses of the MABS signal to simple stimuli were generally similar to those of the CA, but were more stable statistically. Thus, the MABS is better suited for studying the activity of populations of neurons. The responses to tones near the best frequency were strongly influenced by a second tone, even when the second tone was outside the single-tone response area. These influences could be both facilitatory and suppressory. They could not be predicted from the responses to single tones. The responses to the nine-tone stimuli could be explained qualitatively by the responses to the two-tone stimuli. It is concluded that the population responses in primary auditory cortex are shaped by the contributions of the individual frequencies appearing in the stimulus and by the interactions between pairs of frequencies. Interactions between stimulus components are therefore a necessary component of any attempt to explain the processing of complex sounds in the auditory cortex. They may play a role in a global representation of the stimulus spectrum in the primary auditory cortex. The presence of higher-order interactions cannot be excluded by the results presented here.

Acoustic Stimulation↗

PubMed1987

Transcoding sound to spelling: single or multiple sound unit correspondence?

We report a detailed analysis of the written spelling of an aphasic patient, KT, in whom no viable comprehension could be demonstrated despite accurate repetition and fluent speech (transcortical sensory aphasia). His spelling conformed in all respects with the definition of an orthographic/lexical dysgraphic such that his writing of regular, orthographically unambiguous words and nonsense syllables was entirely satisfactory. Lexical variables such as word class or word frequency had no effect on his performance. Irregular or ambiguously spelled words were selectively impaired. An independent measure of orthographical ambiguity was defined in relation to the frequency with which a phoneme was represented by a particular grapheme and the number of alternative graphemes for the same sound. For the majority of sounds studied, KT was able to demonstrate the use of all the most frequent alternative transcoding units for each sound but he did not use them in the same frequency with which they occurred in written English. Thus his performance bore little or no relationship to predictions based on single phoneme/grapheme counts and there was unequivocal evidence for his ability to use multiple sound-unit correspondences.

Aphasia, Wernicke↗

PubMed1998

Real-time separation of discontinuous adventitious sounds from vesicular sounds using a fuzzy rule-based filter.

The separation of pathological discontinuous adventitious sounds (DAS) from vesicular sounds (VS) is of great importance to the analysis of lung sounds since DAS are related to certain pulmonary pathologies. An automated way of revealing the diagnostic character of DAS, by isolating them from VS, based on their nonstationarity, is presented in this paper. The proposed algorithm uses two adaptive network-based fuzzy inference systems to compose a generalized fuzzy rule-based stationary-nonstationary filter (GFST-NST). The training procedure of the fuzzy inference systems involves the outputs of the wavelet transform-based stationary-nonstationary filter (WTST-NST), proposed by Hadjileontiadis and Panas [1]. The basic idea of the GFST-NST was initially proposed by the authors with the introduction of the fuzzy rule-based stationary-nonstationary filter (FST-NST) [2], tested with the separation of crackles from VS. The main contribution of this paper is the modification of the structure of the FST-NST filter to a serial-type fuzzy filter that, unlike the parallel operation of the FST-NST filter, sends a predicted stationary signal (VS) into the predictor of the nonstationary (DAS). Applying the GFST-NST filter to fine-coarse crackles and squawks, selected from three lung sound databases, the coherent structure of DAS is revealed and they are separated from VS. The separation performance of the GFST-NST filter was evaluated through quantitative and qualitative indexes that proved its efficiency and superiority against the FST-NST filter. When compared to the WTST-NST filter, the GFST-NST filter performed similarly in accuracy and objectiveness, but in a faster way. Thus, the GFST-NST filter combines the separation accuracy of the WTST-NST filter with the real-time implementation of the FST-NST filter, so it can easily be used in clinical medicine as a module of an integrated intelligent patient evaluation system.

Auscultation↗

PubMed1998

Production of sound waves by bacterial cells and the response of bacterial cells to sound.

Bacterial cells enhance the proliferation of neighboring cells under stress conditions by emitting a physical signal. Continuous single sine sound waves produced by a speaker at frequencies of 6-10, 18-22, and 28-38 kHz promoted colony formation by Bacillus carboniphilus under non-permissive stress conditions of high KCl concentration and high temperature. Furthermore, sound waves emitted from cells of Bacillus subtilis at frequencies between 8 and 43 kHz with broad peaks at approximately 8.5, 19, 29, and 37 kHz were detected using a sensitive microphone system. The similarity between the frequency of the sound produced by B. subtilis and the frequencies that induced a response in B. carboniphilus and the previously observed growth-promoting effect of B. subtilis cells upon B. carboniphilus through iron barriers, suggest that the detected sound waves function as a growth-regulatory signal between cells.

Journal Article↗

PubMed1988

Fetal response to sound stimulation: preliminary report exploring use of sound stimulation in routine obstetrical ultrasound examinations.

An artificial larynx was used to sound-stimulate 693 human fetuses with gestational age ranging from 21 to 42 weeks. Fetuses were monitored, with simultaneous ultrasound, for immediate, increased motor activity after the stimulus. Each was scored as either demonstrating for startle response or having no visible response to the stimulus. Four zones of gestational development were determined: nonstartle zone (gestation age below 24 weeks), in which none reacted; transitional zone A (24 to 27 weeks), in which 30% reacted, transitional zone B (27 to 30 weeks), in which 86% reacted; and startle zone (above 31 weeks), in which 96% reacted. A review of the 17 patients not responding to sound in the startle zone, revealed a wide spectrum of complications of pregnancy in eight, including sepsis, meconium aspiration, short umbilical cord, abruption of the placenta, bradycardia, and death, while nine were without recorded abnormalities. Sound stimulation designed to elicit a startle response on ultrasound may have some potential benefit in identifying fetuses at risk or needing closer physiologic evaluation. Adding sound stimulation to the routine ultrasound study may warrant further study.

Acoustic Stimulation↗

PubMed2000

["Sound, unsound around the Sound". A congress report on health differences between Denmark and Sweden].

During the past 10 years, researchers on both sides of The Sound in the so-called Oresund region have worked together to analyze the causes of the observed differences in life expectancy between Denmark and Sweden. The region includes Copenhagen and North Zealand and the county of Scania in southern Sweden, with Malmö as its largest city. Both Denmark and Sweden held top rankings among OECD-countries in 1970 regarding life expectancy at birth. In 1990 Denmark had fallen to a bottom ranking, while Sweden was still at the top. At a scientific meeting in Malmö on January 26-27, 2000, some 60 presentations were made concerning differences and similarities in health measures on the two sides of the sound which divides the two countries. On the Swedish side, life expectancy is 3-4 years longer than on the Danish side. Paramount among explanations are higher mortality figures due to smoking and alcohol-related diseases on the Danish side, both in men and women (most pronounced). Minor contributions to the differences are suicides and traffic accidents. Historically, Denmark and Sweden have much in common. Until 1658, Scania, the Swedish county to the east of The Sound was part of Denmark. During the past 150 years rather impressive cultural differences have developed. Smoking prevalence and alcohol consumption are more than twice as high on the Danish side of the sound. In coming years, researchers, representatives for the health service systems and others will work together in order to prevent disease and promote health in the Oresund region. The conference was arranged by the Medicon Valley Academy, an EU-supported enterprise seeking to stimulate research and development within the health sector in the Oresund region (also known as Medicon Valley).

Alcohol Drinking↗

PubMed2000

["Sound and unsound around the Sound". A congress report on health differences between Denmark and Sweden].

During the past 10 years, researchers on both sides of The Sound in the so-called Oresund region have worked together to analyze the causes of the observed differences in life expectancy between Denmark and Sweden. The region includes Copenhagen and North Zealand and the county of Scania in southern Sweden, with Malmö as its largest city. Both Denmark and Sweden held top rankings among OECD-countries in 1970 regarding life expectancy at birth. In 1990 Denmark had fallen to a bottom ranking, while Sweden was still at the top. At a scientific meeting in Malmö on January 26-27, 2000, some 60 presentations were made concerning differences and similarities in health measures on the two sides of the sound which divides the two countries. On the Swedish side, life expectancy is 3-4 years longer than on the Danish side. Paramount among explanations are higher mortality figures due to smoking and alcohol-related diseases on the Danish side, both in men and women (most pronounced). Minor contributions to the differences are suicides and traffic accidents. Historically, Denmark and Sweden have much in common. Until 1658, Scania, the Swedish county to the east of The Sound was part of Denmark. During the past 150 years rather impressive cultural differences have developed. Smoking prevalence and alcohol consumption are more than twice as high on the Danish side of the sound. In coming years, researchers, representatives for the health service systems and others will work together in order to prevent disease and promote health in the Oresund region. The conference was arranged by the Medicon Valley Academy, an EU-supported enterprise seeking to stimulate research and development within the health sector in the Oresund region (also known as Medicon Valley).

Alcohol Drinking↗

PubMed2000

[Sound and unsound around the Sound. A congress report on health differences between Denmark and Sweden].

During the past 10 years, researchers on both sides of The Sound in the so-called Oresund region have worked together to analyze the causes of the observed differences in life expectancy between Denmark and Sweden. The region includes Copenhagen and North Zealand and the county of Scania in southern Sweden, with Malmö as its largest city. Both Denmark and Sweden held top rankings among OECD-countries in 1970 regarding life expectancy at birth. In 1990 Denmark had fallen to a bottom ranking, while Sweden was still at the top. At a scientific meeting in Malmö on January 26-27, 2000, some 60 presentations were made concerning differences and similarities in health measures on the two sides of the sound which divides the two countries. On the Swedish side, life expectancy is 3-4 years longer than on the Danish side. Paramount among explanations are higher mortality figures due to smoking and alcohol-related diseases on the Danish side, both in men and women (most pronounced). Minor contributions to the differences are suicides and traffic accidents. Historically, Denmark and Sweden have much in common. Until 1658, Scania, the Swedish county to the east of The Sound was part of Denmark. During the past 150 years rather impressive cultural differences have developed. Smoking prevalence and alcohol consumption are more than twice as high on the Danish side of the sound. In coming years, researchers, representatives for the health service systems and others will work together in order to prevent disease and promote health in the Oresund region. The conference was arranged by the Medicon Valley Academy, an EU-supported enterprise seeking to stimulate research and development within the health sector in the Oresund region (also known as Medicon Valley).

Alcohol Drinking↗

PubMed2004

[Implementation of habituation theory to pulsatile somato-sounds (tinnitus): the heart valve prosthesis sound model].

OBJECTIVES: To evaluate the habituation process to mechanical heart valve prosthesis sound as a model to understand the pulsatile tinnitus or somatosound perception changes. STUDY DESIGN: Transversal descriptive. PATIENTS: One hundred and fifty patients referred to a University Hospital for one or two mechanical heart valve implantation. OUTCOME MEASURES: Questionnaire sent by mail for prosthesis sound loudness and interference in quality of life evaluation. Detection of factors related to habituation process development. RESULTS: Eighty three percent of the patients perceived their prosthesis sound continuously, while only a 17% showed high levels of annoyance. No significative differences in prosthesis type and localization were described. Anxiety was the most important factor for loudness increase. The average of visual analogical scales on sound loudness and annoyance showed mild values (3.7 and 1.9 respectively). CONCLUSIONS: Extensive medical counselling or tinnitus retraining therapy (TRT) program for most severe cases, are proposed for pulsatile tinnitus management when etiological treatment cannot be available.

Adult↗

PubMed1989

Quantification of heart sounds interference with lung sounds.

An index to quantify the contamination of lung sounds by heart sounds is described. Using the index, the efficacy of high pass filtering and adaptive filtering methods for the reduction of heart sounds is evaluated.

Heart Auscultation↗

PubMed1989

Interaural sound pressure level differences associated with sound-source locations in the frontal hemifield of the domestic cat.

Interaural sound pressure level differences (ILDs) associated with a range of sound-source azimuths and elevations in the frontal hemifields of four cats were measured for each of seven pure-tone stimuli ranging in frequency from 2-32 kHz. The overall pattern of ILD across location at each frequency was remarkably similar in all cats. At 2, 4 and 8 kHz the relationships of ILD to azimuth and elevation were generally monotonic with ILD increasing with increasing azimuth. At 12 kHz and above, however, non-monotonic relationships developed and circumscribed regions of particularly large, positive and negative ILDs were apparent. That ILDs associated with many sound-source locations on the near side of the head are negative in sign has not been widely noted in the previous literature. The data obtained in this study were compared with those from previous studies and the acoustical mechanisms likely to have contributed to production of the observed ILDs were considered. Some implications of the data for auditory localization in three-dimensional space were discussed.

Air Pressure↗

PubMed2000

SEM search for sound production and sound perception organs in a variety of Drosophila species.

The discovery of new song types in Hawaiian Drosophila species has raised a question of alternative sound production and sound perception mechanisms in Drosophila. For example D. disjuncta males, which produce song with a carrier frequency of 5,000-6,000 Hz, do not vibrate their wings but only tremble them in a very small amplitude while singing. In our SEM search we found at the wing base of the flies of this species a special structure which could play a part in song production. Our search for auditory sense organs in Drosophila species revealed that the aristae on fly antennae are structurally not as simple as has been assumed. In Hawaiian D. planitibia subgroup species, the fly aristae are more regular than in other Drosophila species and they are also covered with small hairs. We did not find any sign of tympanic hearing organs in any of the studied species, but we discovered on fly legs and wings sensilla which could play a part in sound/vibration perception. Our SEM survey provides a good starting point in the search for alternative pathways for sound production and perception via transmission electron microscopy combined with behavioral studies and electrophysiological recordings in Hawaiian Drosophila species.

Animals↗

PubMed1976

Auscultatory perception of the fourth heart sound: effects of interval form fourth to first sound (S4-S1) and aging.

A clinically heterogeneous group of 48 subjects (aged 19 to 76 years) were searched for a fourth heart sound (S4) by three independent "blind" auscultators. Phonocardiograms recorded immediately after auscultation were measured by another "blind" observer. An S4 was identified in 32 subjects (67 per cent) in phonocardiograms with nominal filter peaks of both 70 and 35 hertz. Results in these subjects revealed two groups by auscultatory performance: those with an "easily heard" and those with an "easily missed" S4. Subjects with an "easily missed" S4 were significantly younger than those with an "easily heard" S4 (31.2 +/- 2.8 years versus 50.0 +/- 4.0 years, P less than 0.001). P-R and P-S4 intervals and relative amplitude of S4 (ratio of fourth to first heart sound [S1] amplitude) were not significantly different in the two groups. Splitting of the first heart sound (S1) was observed more frequently in the phonocardiogram of patients with an "easily missed" S4, but this trend did not reach statistical significance. The interval between S4 and the low frequency component of S1 was significantly short in those with an "easily heard" S4 (49.4 +/- 4.1 msec versus 70.0 +/- 5.0 msec, P less than 0.005). The mean S4-S1 (low frequency component) interval for the group with an "easily heard" S4 approximated 1 cycle length for S4 vibrations, a finding consistent with temporal acoustic summation. An alternate hypothesis is modification of S1.

Adult↗