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PubMed2002

Sound stimulation via bone conduction for tinnitus relief: a pilot study.

For some patients suffering from tinnitus, an external sound stimulator can offer some mitigation. Based on our positive experience with the bone-anchored hearing aid (BAHA), it seems possible to transmit a masking or habituating sound via bone conduction. A potential advantage of bone-conducted sound is that it is transmitted to the cochlea without affecting the normal hearing via the external and middle ear. The present pilot study, on patients who use a conventional BAHA and who experience mild-to-moderate tinnitus, shows that bone-conducted sound has the potential to relieve tinnitus in the same way as air-conducted sound. It was also found that these patients, having a significant conduction hearing loss, required conventional sound amplification via a BAHA simultaneously with the stimulus provided by the bone-anchored sound stimulator (BASS). Further studies on patients with more severe tinnitus must be conducted in order to justify the use of a BASS for tinnitus relief.

Acoustic Stimulation↗
PubMed1985

Effect of cyclic sound cues on sexual development in nonphotostimulated Japanese quail.

The influence of cyclic ambient sound stimuli on sexual development was studied in nonphotostimulated [6 hr light:18 hr dark (16L:18D)] Japanese quail (Coturnix coturnix japonica). The incidence of accelerated gonadal development was reduced when ambient daily sound stimuli were attenuated by the presence of a white noise mask in the animal quarters. In a second experiment nonphotostimulated (9L:15D) male quail showed a phase-dependent testicular response to a daily 3-hr radio broadcast presented at different portions of the day. The radio sound stimulus induced a higher incidence of accelerated gonadal development when presented 6 hr prior to the photophase than when presented either 3 hr prior to the photophase or when presented coincidently with the photophase onset. In a third experiment locomotion was monitored in nonphotostimulated quail (9L:15D) with a 3-hr radio sound stimulus presented 6 hr prior to photophase onset. The onset of a daily locomotor activity pattern was associated with radio sound in some individuals, but sound-induced locomotion was not consistently associated with sound-induced accelerated gonadal development.

Acoustic Stimulation↗
PubMed2000

Specificity of auditory implicit and explicit memory: is perceptual priming for environmental sounds exemplar specific?

Previous research (Stuart & Jones, 1995) has suggested that identification of environmental sounds may be mediated by abstract sound recognition units. This article reports the results of four repetition priming experiments that find evidence to the contrary. Participants attempted to identify environmental sounds from the initial sound stems (Experiments 1 and 2) or when the sounds were embedded in white noise (Experiments 3 and 4). Repetition of an identical exemplar sound led to more priming than did exposure to a different exemplar, provided that the perceptual difference between the two different exemplars was sufficiently large. Such an exemplar specificity effect was independent of the depth of prior encoding. A similar exemplar specificity effect was also found in explicit stem-cued recall (Experiments 1 and 2) and recognition (Experiment 3). Depth of encoding dissociated performance on tests of repetition priming and explicit memory. These results suggest that a significant amount of specific information is remembered, both implicitly and explicitly, to characterize individual exemplars of a sound category.

Association Learning↗
PubMed1999

Human complex sound analysis.

The analysis of complex sound features is important for the perception of environmental sounds, speech and music, and may be abnormal in disorders such as specific language impairment in children, and in common adult lesions including stroke and multiple sclerosis. This work addresses the problem of how the human auditory system detects features in complex sound, and uses those features to perceive the auditory world. The work has been carried out using two independent means of testing the same hypotheses; detailed psychophysical studies of neurological patients with central lesions, and functional imaging using positron emission tomography and functional magnetic resonance imaging of normal subjects. The psychophysical and imaging studies have both examined which brain areas are concerned with the analysis of auditory space, and which are concerned with the analysis of timing information in the auditory system. This differs from many previous human auditory studies, which have concentrated on the analysis of sound frequency. The combined lesion and functional imaging approach has demonstrated analysis of the spatial property of sound movement within the right parietal lobe. The timing work has confirmed that the primary auditory cortex is active as a function of the time structure of sound, and therefore not only concerned with frequency representation of sounds.

Auditory Perception↗
PubMed2001

Predicting the sound power and impact of a wastewater treatment plant.

Several process units at a wastewater treatment plant (WWTP) can produce a significant level of sound and thus induce sound nuisance for nearby residents. The risk for sound nuisance should be considered by making a prognosis of sound impact in an early project phase (planning, design). A prognosis requires information with respect to the sound characteristics of the different process units. This paper reports the development of empirical models for the sound power of relevant process units in the water line at Aquafin WWTPs. The used methodology for model derivation and validation allowed us to minimize the required number of measurements. Besides the methodology, the paper describes in detail the derivation and validation of the empirical model for the splashing water of screw pumps. Also the use of all the derived empirical models to determine the sound impact of a wastewater treatment plant at close distance is illustrated with a case-study.

Consumer Behavior↗
PubMed2001

Balancing speech intelligibility versus sound exposure in selection of personal hearing protection equipment for Chinook aircrews.

BACKGROUND: Aircrews are often exposed to high ambient sound levels, especially in military aviation. Since long-term exposure to such noise may cause hearing damage, selection of adequate hearing protective devices is crucial. Such devices also affect speech intelligibility. When speech intelligibility and hearing protection lead to conflicting requirements, a compromise must be reached. The selection of personal equipment for RNLAF Chinook aircrews is taken as an example of this process. METHODS: Sound attenuation offered by aircrew helmets and ear plugs was measured using a standardized method. Sound attenuation results were used to calculate sound exposure. Objective predictions of speech intelligibility were calculated using the Speech Transmission Index (STI) method. Subjective preference was investigated through a survey among 28 experienced aircrew members. RESULTS: The use of ear plugs in addition to a (RNLAF standard) helmet may lead to a significant reduction of sound exposure. Using ear plugs that offer high sound attenuation, instead of using a less attenuating type, gives a little additional reduction of sound exposure, at the expense of a large reduction in speech intelligibility. Hence, it is better to use 'light' ear plugs. Better performance still is offered by Communications Earplugs, ear plugs featuring integrated miniature earphones. Results from the user preference survey correspond well with objective measurement results. CONCLUSIONS: In the case of the RNLAF Chinook, the best solution is using Communications EarPlugs in combination with a standard helmet. The Chinook case clearly illustrates that hearing protection and speech intelligibility should be treated as connected issues.

Aerospace Medicine↗
PubMed2002

Distinct gamma-band evoked responses to speech and non-speech sounds in humans.

To understand spoken language, the human brain must have fast mechanisms for the representation and identification of speech sounds. Stimulus-induced synchronization of neural activity at gamma frequencies (20-80 Hz), occurring in humans at 200-300 msec from stimulus onset, has been suggested to be a possible mechanism for neural object representation. Auditory and visual stimuli also evoke an earlier (peak <100 msec) gamma oscillation, but its dependence on high-level stimulus parameters and, thereby, its involvement in object representation has remained unclear. Using whole-scalp magnetoencephalography, we show here that responses evoked by speech and non-speech sounds differed in the gamma-frequency but not in the low-frequency (0.1-20 Hz) band as early as 40-60 msec from stimulus onset. The gamma-band responses to the speech sound peaked earlier in the left than in the right hemisphere, whereas those to the non-speech sound peaked earlier in the right hemisphere. For the speech sound, there was no difference in the response amplitude between the hemispheres at low (20-45 Hz) gamma frequencies, whereas for the non-speech sound, the amplitude was larger in the right hemisphere. These results suggest that evoked gamma-band activity may indeed be sensitive to high-level stimulus properties and may hence reflect the neural representation of speech sounds. Consequently, speech-specific neuronal processing may commence no later than 40-60 msec from stimulus onset, possibly in the form of activation of language-specific memory traces.

Acoustic Stimulation↗
PubMed1991

Maternal perception of sound-provoked fetal movement as a test of antepartum fetal wellbeing.

Maternal perception of sound-provoked fetal movement test was studied on 506 occasions in 443 women with obstetric or medical antenatal risk factors after 26 weeks gestation. The response was compared with a nonstress test (NST) performed immediately after a three-second vibroacoustic stimulation with an electronic artificial larynx. A positive response to sound stimulation, recorded as a fetal movement by the mother, occurred on 497 occasions (97.3%) and was accompanied by a reactive NST on 484 occasions; giving a specificity of 99.6 per cent and a negative predictive value of 97.4 per cent. An inconclusive or negative response to sound (2.7%) had a sensitivity of 35.0 per cent and a positive predictive value for a nonreactive NST of 77.8 per cent. Results of sound-provoked fetal movement test and NST, performed within a week of delivery, in 434 women were compared with fetal outcome. The maternal perception of sound-provoked fetal movement test had better specificity (99.1% vs 96.9%), positive predictive value (55.6% vs 35.0%) for poor fetal outcome than the NST, although its sensitivity (50.0% vs 70.0%) and negative predictive value (98.8% vs 99.3%) were lower. Maternal perception of sound-provoked fetal movement test may suffice as an inexpensive and simple method of evaluating antepartum fetal well-being in risk situations. When the mother does not feel any sound provoked fetal movement, NST is then performed. This clinical application can be helpful in a primary health care setting where rapid assessment of fetal health at risk is required.

Acoustic Stimulation↗
PubMed1996

Detection and recognition of octave-band sound effects.

The goal of this study was to determine whether selected sound effects that are spectrally limited to an octave band width could be used as alternative stimuli to pure tones when testing children and other special populations. The uniqueness of octave-band sound effects is that they retain the natural character of everyday sounds while providing frequency-specific information about hearing sensitivity. In this study, 20 normal-hearing adults were asked to detect and recognize octave-band filtered musical and environmental sounds presented in quiet and in multitalker noise. Detection and recognition thresholds for the filtered sound effects were compared with respective pure-tone thresholds obtained at 250, 500, 1000, 2000, and 4000 Hz for the same subjects. Results indicate that filtered sound effects are a promising alternative to pure-tone stimuli for use in audiometric tests. Applications and limitations of filtered sound effects as test stimuli for testing children and adults are discussed.

Adolescent↗
PubMed1996

Bond strength of composite to sound and artificial carious dentin.

PURPOSE: To determine the in vitro bond strength of a composite (Herculite XRV) to sound dentin and artificial carious lesions in dentin. MATERIALS AND METHODS: Buccal and lingual surfaces from extracted human molar teeth were ground to expose sound dentin surfaces. The buccal surface was maintained as sound dentin, while an artificial carious lesion was created in the lingual surface using an acidified gelatin gel. A bonding agent (Optibond) was applied to both buccal and lingual surfaces with and without prior etching with 37.5% phosphoric acid. The composite was applied and debonded under tension after 24 hours in water at 37 degrees C. RESULTS: Both sound dentin (23.1 MPa) and etched sound dentin (22.2 MPa) had similar bond strengths, whereas artificial carious lesions in dentin that had been etched (11.8 MPa) and non-etched dentin lesions (8.8 MPa) had significantly lower bond strengths. Adhesive failures were greatest for dentin lesions (60-95%) and least for sound dentin(40-50%). Etching with phosphoric acid did not improve the bond strength of composite to sound dentin or artificial carious lesions in dentin.

Acid Etching, Dental↗
PubMed1998

[Psychopathological alteration of the auditory structure in schizophrenia; "the experience of no-sounds"].

According to recent cognitive theories, the greater part of the perceptional meaning and representative meaning are both pre-determined, or pre-organized as a set of meaning, which has a biophysiological and socio-cultural origin. Humans however, drive some kind of sensational Gestalt from each sense organ, and this is incapable of being transformed into language (representative pre-meaning), this enabling us to experience the possibility of truly private meaning in our own right. The author has emphasized this two moments of the meaning, that is, private moments of meaning vs. institutional moments. The author has offered the phenomenological hypothesis of auditory experience and elaborated the relation between these two moments in it. Then, the author has testified its validity in the process of describing and analysing the pathological alteration of auditory sensation in schizophrenia. Auditory space is thought to be differentiated into a three-dimensional structure. That is, a dimension of background, a dimension of signs, and a dimension of symbols, and we accept environmental-sounds, event-sounds, symbolic sounds in each level. Close investigations about 5 schizophrenics revealed that these patients undergo a strange silent experience before the onset of delusional ideas, descriptively and phenomenologically, this phenomenon appeared to be initiated by the deprivation of the dimension of background sounds (referred to as "the experience of no-sounds"). This experiences often occurred especially when they are eager to listen to the surrounding sounds (for example, noises in the neighborhood, classroom chatter), in order to solve their own interpersonal difficulties. Furthermore, the author described the ambivalent nature of patients' thinking in this pathological auditory situation, in which one idea of the polarity of dichotomy was forced to switch to the another one, influenced by an attribute of surrounding sounds. With regard to this aspect, the patients experienced both the physiological changes in the auditory structure as well as the psychological turmoil. The author has emphasized the need to appreciate this ambiguous nature of the psychological context mixed with the physiological context, which is supposed to be very important from psychotherapeutical viewpoint.

Adult↗
PubMed2006

Audio spectrum and sound pressure levels vary between pulse oximeters.

PURPOSE: The variable-pitch pulse oximeter is an important intraoperative patient monitor. Our ability to hear its auditory signal depends on its acoustical properties and our hearing. This study quantitatively describes the audio spectrum and sound pressure levels of the monitoring tones produced by five variable-pitch pulse oximeters. METHODS: We compared the Datex-Ohmeda Capnomac Ultima, Hewlett-Packard M1166A, Datex-Engstrom AS/3, Ohmeda Biox 3700, and Datex-Ohmeda 3800 oximeters. Three machines of each of the five models were assessed for sound pressure levels (using a precision sound level meter) and audio spectrum (using a hanning windowed fast Fourier trans-form of three beats at saturations of 99%, 90%, and 85%). RESULTS: The widest range of sound pressure levels was produced by the Hewlett-Packard M1166A (46.5 +/- 1.74 dB to 76.9 +/- 2.77 dB). The loudest model was the Datex-Engstrom AS/3 (89.2 +/- 5.36 dB). Three oximeters, when set to the lower ranges of their volume settings, were indistinguishable from background operating room noise. Each model produced sounds with different audio spectra. Although each model produced a fundamental tone with multiple harmonic overtones, the number of harmonics varied with each model; from three harmonic tones on the Hewlett-Packard M1166A, to 12 on the Ohmeda Biox 3700. There were variations between models, and individual machines of the same model with respect to the fundamental tone associated with a given saturation. CONCLUSION: There is considerable variance in the sound pressure and audio spectrum of commercially-available pulse oximeters. Further studies are warranted in order to establish standards.

Equipment Design↗
PubMed2006

Sound component duration of healthy human pharyngoesophageal swallowing: a gender comparison study.

Cervical auscultation is a noninvasive technique for studying swallowing that was first used in the 1960s. The aim of our study was to use the numeric acoustic recording technique for analyzing swallowing sound signals in healthy subjects while they ingested a defined volume and consistency of a specific substance. Twenty males and ten females were included in the study and given 10 ml of a barium suspension to swallow. A microphone was placed on the skin overlying the lateral border of the trachea, directly under the inferior border of the cricoid, and connected to a computer. For each sound recording, the total duration of the sound (td), the number (n) of sound components (SC), the duration of each SC (c1, c2, c3,...), and the intervals (i1, i2,...) between the SCs were measured. For all the recordings, the mean durations of acoustic parameters (TDm, C1m, C2m, C3m, I1m, I2m) were calculated and compared by using Student's t test. In the 20 male subjects, the mean acoustic parameters were calculated (MTDm, MC1m, MC2m, MC3m, MI1m, MI2m) and compared with the mean acoustic parameters (FTDm, FC1m, FC2m, FC3m, FI1m, FI2m) in the ten females by using a Wilcoxon nonparametric statistical test. We were able to interpret 80% of the recordings. The TDm was 710 +/- 28 ms. Three main SCs were detected: C1m = 100 +/- 56, C2m = 150 +/- 90, C3m = 80 +/- 54 ms; I1m = 100 +/- 66, I2m = 190 +/- 120 ms. No significant difference in these parameters was observed with respect to gender. This study enabled us to decompose the swallowing sounds into three main SCs and to quantify their normal durations. These results should prove useful for the assessment of sound variations in pathologic conditions.

Acoustics↗
PubMed1986

Effects of lung volume and airflow on the frequency spectrum of vesicular lung sounds.

UNLABELLED: The purpose of this study was to determine whether the vesicular lung sound frequency spectrum is affected by changes in lung volume and airflow. Nine healthy young nonsmokers were studied. The dependent variables were the points that divide the power spectrum of the vesicular lung sound into quarters (1st, 2nd and 3rd quartiles (Q1, Q2 and Q3]. Recording sites were the right upper anterior (RUL) and lower posterior (RLL) chest wall. Lung sounds were high-pass filtered at 100 Hz. To evaluate the effect of volume, lung sounds were recorded during an inspiratory vital capacity (VC) maneuver at near constant airflow rates. The spectral parameters were determined at each sixth of the VC. To assess the effects of airflow, 5 of the subjects breathed from resting lung volume at peak inspiratory airflows of between 1 and 3.0 L/sec for a total of 16 breaths each and the frequency parameters of the lung sounds occurring during peak inspiratory airflows were determined. RESULTS: Volume effects: only at the RUL was there a small but significant decrease in all three parameters with increasing lung volume. Airflow effects: all parameters were independent of airflow except for a weakly positive relationship (r = 0.285, P less than 0.05) for Q3 at the RUL location. Individually, there were weakly significant trends in three of the five subjects. These data suggest that the frequency composition of the vesicular lung sound in groups of healthy adults is not systematically affected by changes in lung volume or airflow.

Adult↗
PubMed1979

Monitoring the state of the human airways by analysis of respiratory sound.

A mechanism whereby sound is generated by the motion of vortices in the human lung is described. This mechanism is believed to be responsible for most of the sound which is generated both on inspiration and expiration in normal lungs. Mathematical expressions for the frequencies of sound generated, which depend only upon the axial flow velocity and diameters of the bronchi, are derived. This theory allows the location within the bronchial tree from which particular sounds emanate to be determined. Redistribution of pulmonary blood volume following transition from Earth gravity to the weightless state probably alters the caliber of certain airways and doubtless alters sound transmission properties of the lung. We believe that these changes can be monitored effectively and non-invasively by spectral analysis of pulmonary sound.

Adaptation, Physiological↗
PubMed2006

Effect of nasal valve area on inspirator nasal sound spectra.

OBJECTIVE: We have researched the effects of nasal valve area on the inspiratory nasal sound spectra in this study. STUDY DESIGN AND SETTING: We have spectral analyzed and recorded the inspiratory nasal sound in 22 healthy people with and without the Cottle maneuver. RESULTS: We have found an increase in sound intensity at high frequency in the sound analyses of the subjects without the Cottle maneuver; whereas, a decrease in sound intensity at high frequency was found in subjects with the Cottle maneuver. CONCLUSIONS: The nasal valve area plays an important role in the transformation of the nasal airflow from a laminar pattern to a more turbulent one. This condition affects nasal sound spectra and produces a marked shift upward in frequencies in the spectra. This method may be a new way of evaluating the nasal valve area. EBM RATING: C-4.

Adult↗
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

Computer aided gnathosonic analysis: distinguishing between single and multiple tooth impact sounds.

Watt developed a classification of tooth contact sounds that distinguished between the short sharp, reproducible sounds heard when the teeth meet simultaneously and the dull prolonged, poorly reproducible sounds heard when tooth contacts are sequential. However, when a large occlusal prematurity, for instance a high restoration, is introduced, tooth contact sounds are also short sharp and highly reproducible. In this study, a method of distinguishing single from multiple tooth contact sounds is described, based on an analysis of the phase and amplitude of sounds detected by headphones placed over the ears.

Adult↗