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At least 307 records · Page 17Linked to original sources
PubMed2005

Long-term exposure to occupational noise alters the cortical organization of sound processing.

OBJECTIVE: Long-term exposure to noise may cause an altered hemispheric lateralization of speech processing even in silent conditions. We examined whether this lateralization shift is speech specific or occurs also for other sounds. METHODS: Brain responses from 10 healthy noise-exposed workers (>5 years) and 10 matched controls were recorded with a 32-channel electroencephalogram in two conditions, one including standard and deviant speech sounds, the other non-speech sounds, with novel sounds in both. RESULTS: The deviant-sound elicited mismatch negativity (MMN) was larger to non-speech than speech sounds in control subjects, while it did not differ between the sound types in the noise-exposed subjects. Moreover, the MMN to speech sounds was lateralized to the right hemisphere in exposed workers, while it was left-hemisphere predominant in control subjects. No group topography difference was found for non-speech sounds. The deviant sounds that were close in formant space to the standards elicited a longer MMN latency in both speech and non-speech conditions in exposed subjects than controls. No group differences were found for cortical responses to novel sounds. CONCLUSIONS: Long-term noise exposure altered the strength and the hemispheric organization of speech-sound discrimination and decreased the speed of sound-change processing. SIGNIFICANCE: Subpathological changes in cortical responses to sounds may occur even in subjects without a peripheral damage but continuously exposed to noisy auditory environments.

Adult↗
PubMed1998

A field survey on the annoyance caused by sounds from large firearms and road traffic.

Subjective reactions to artillery sounds were determined for over 400 respondents divided among 17 different residential areas. Also, for the same respondents, the subjective effects of road-traffic sounds were determined enabling a comprehensive comparison of the dose-response relations. For the sake of comparison with other field surveys, the noise dose for the shooting sounds was, among other things, expressed as the yearly average C-weighted day-night level (CDNL) and that for the road-traffic sounds was expressed as the A-weighted day-night level (ADNL). Similarly, for both sound types the community response was expressed as the percentage of respondents being "highly annoyed." From the comparison of the two dose-response relationships it could be concluded that for numerically equal day-night levels, the artillery sounds were more annoying than the road-traffic sounds. Overall, the difference was equivalent to the change in annoyance produced by a 5-dB shift in the yearly average day-night levels of the sounds. With equal day-night levels for "downwind" conditions, the artillery and road-traffic sounds were equally annoying. Results from the present highly controlled field survey provided a new opportunity to optimize the parameter values in Schomer's rating procedure y = (1/beta)(LCE-PNSE) + PNSE, in which the noise exposure for impulsive sounds (y) is expressed as the A-weighted SEL of equally annoying vehicle sounds. PNSE represents the point at which the impulsive and vehicle sounds with numerically equal levels are also equally annoying. With PNSE fixed at 103 dB, an optimal solution was found with slope beta set to 1.3. With the previously recommended slope beta = 0.67, the rating sound level for artillery sounds would be underestimated by almost 12 dB.

Adult↗
PubMed2005

Underwater hearing and sound localization with and without an air interface.

HYPOTHESIS: Underwater hearing acuity and sound localization are improved by the presence of an air interface around the pinnae and inside the external ear canals. BACKGROUND: Hearing threshold and the ability to localize sound sources are reduced underwater. The resonance frequency of the external ear is lowered when the external ear canal is filled with water, and the impedance-matching ability of the middle ear is significantly reduced due to elevation of the ambient pressure, the water-mass load on the tympanic membrane, and the addition of a fluid-air interface during submersion. Sound lateralization on land is largely explained by the mechanisms of interaural intensity differences and interaural temporal or phase differences. During submersion, these differences are largely lost due to the increase in underwater sound velocity and cancellation of the head's acoustic shadow effect because of the similarity between the impedance of the skull and the surrounding water. METHODS: Ten scuba divers wearing a regular opaque face mask or an opaque ProEar 2000 (Safe Dive, Ltd., Hofit, Israel) mask that enables the presence of air at ambient pressure in and around the ear made a dive to a depth of 3 m in the open sea. Four underwater speakers arranged on the horizontal plane at 90-degree intervals and at a distance of 5 m from the diver were used for testing pure-tone hearing thresholds (PTHT), the reception threshold for the recorded sound of a rubber-boat engine, and sound localization. For sound localization, the sound of the rubber boat's engine was randomly delivered by one speaker at a time at 40 dB HL above the recorded sound of a rubber-boat engine, and the diver was asked to point to the sound source. The azimuth was measured by the diver's companion using a navigation board. RESULTS: Underwater PTHT with both masks were significantly higher for frequencies of 250 to 6000 Hz when compared with the thresholds on land (p <0.0001). No differences were found in the PTHT or the reception threshold for the recorded sound of a rubber-boat engine for dry or wet ear conditions. There was no difference in the sound localization error between the regular mask and the ProEar 2000 mask. CONCLUSIONS: The presence of air around the pinna and inside the external ear canal did not improve underwater hearing sensitivity or sound localization. These results support the argument that bone conduction plays the main role in underwater hearing.

Acoustic Impedance Tests↗
PubMed1999

Sensitivity to simulated directional sound motion in the rat primary auditory cortex.

Sensitivity to simulated directional sound motion in the rat primary auditory cortex. This paper examines neuron responses in rat primary auditory cortex (AI) during sound stimulation of the two ears designed to simulate sound motion in the horizontal plane. The simulated sound motion was synthesized from mathematical equations that generated dynamic changes in interaural phase, intensity, and Doppler shifts at the two ears. The simulated sounds were based on moving sources in the right frontal horizontal quadrant. Stimuli consisted of three circumferential segments between 0 and 30 degrees, 30 and 60 degrees, and 60 and 90 degrees and four radial segments at 0, 30, 60, and 90 degrees. The constant velocity portion of each segment was 0.84 m long. The circumferential segments and center of the radial segments were calculated to simulate a distance of 2 m from the head. Each segment had two trajectories that simulated motion in both directions, and each trajectory was presented at two velocities. Young adult rats were anesthetized, the left primary auditory cortex was exposed, and microelectrode recordings were obtained from sound responsive cells in AI. All testing took place at a tonal frequency that most closely approximated the best frequency of the unit at a level 20 dB above the tuning curve threshold. The results were presented on polar plots that emphasized the two directions of simulated motion for each segment rather than the location of sound in space. The trajectory exhibiting a "maximum motion response" could be identified from these plots. "Neuron discharge profiles" within these trajectories were used to demonstrate neuron activity for the two motion directions. Cells were identified that clearly responded to simulated uni- or multidirectional sound motion (39%), that were sensitive to sound location only (19%), or that were sound driven but insensitive to our location or sound motion stimuli (42%). The results demonstrated the capacity of neurons in rat auditory cortex to selectively process dynamic stimulus conditions representing simulated motion on the horizontal plane. Our data further show that some cells were responsive to location along the horizontal plane but not sensitive to motion. Cells sensitive to motion, however, also responded best to the moving sound at a particular location within the trajectory. It would seem that the mechanisms underlying sensitivity to sound location as well as direction of motion converge on the same cell.

Acoustic Stimulation↗
PubMed2001

PPADS, an ATP antagonist, attenuates the effects of a moderately intense sound on cochlear mechanics.

Increasing attention is being given to the role of neurotransmitters and other signaling substances in the damage induced by intense sound to the cochlea. Adenosine triphosphate (ATP) is one example of a putative neurotransmitter that may alter cochlear mechanics during sound exposure. The purpose of the present study was to test the hypothesis that endogenous extracellular ATP has a role in the generation of the changes in cochlear mechanics induced by moderate intense sound exposure. Guinea pigs were exposed to either: (1) a perilymphatic administration of pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS, 1 mM), an ATP antagonist; (2) a moderately intense sound (6 kHz tone, 95 dB SPL, 15 min); or (3) a combination of the PPADS and the sound. The effects on the cubic distortion product otoacoustic emissions (DPOAEs; 2f1-f2) were monitored using three sets of equal level primaries (f1=9.25 kHz, f2=10.8 kHz, 2f1-f2=7.7 kHz; f1=7.2 kHz, f2=8.4 kHz, 2f1-f2=6 kHz; f1=5.55 kHz, f2=6.5 kHz, 2f1-f2=4.6 kHz). PPADS alone had no effect on the cubic DPOAEs monitored. The intense sound alone suppressed all three cubic DPOAEs. The combination of PPADS with the intense sound induced a suppression of the cubic DPOAEs that was equal to or greater than induced by the intense sound alone at f2=10.8 kHz but was equal to or less than induced by the intense sound at f2=8.4 and 6.5 kHz. After washing the PPADS out of the cochlea with artificial perilymph, all three cubic DPOAEs were suppressed less in the PPADS with intense sound treatment group than in the intense sound alone group. The PPADS appeared to provide protection from the intense sound. Results are consistent with the hypothesis that extracellular ATP is involved in the changes in cochlear mechanics induced by moderately intense sound exposure.

Adenosine Triphosphate↗
PubMed1992

Implications of third heart sounds in patients with valvular heart disease. The Veterans Affairs Cooperative Study on Valvular Heart Disease.

BACKGROUND: The presence of third heart sounds in patients with valvular heart disease is often regarded as a sign of heart failure, but it may also depend on the type of valvular disease. METHODS: We assessed the prevalence of third heart sounds and the relation between third heart sounds and cardiac function in 1281 patients with six types of valvular heart disease. RESULTS: The prevalence of third heart sounds was higher in patients with mitral regurgitation (46 percent) or aortic regurgitation (28 percent) than in those with aortic stenosis (11 percent) or mitral stenosis (8 percent). The left ventricular ejection fraction was significantly lower (P less than 0.001) when a third heart sound was detected in patients with aortic stenosis (0.38, vs. 0.56 in those without third heart sounds) or mixed aortic valve disease (0.40 vs. 0.55). However, the ejection fraction was only slightly lower in patients with mitral regurgitation and third heart sounds (0.51 vs. 0.57, P = 0.03). The pulmonary-capillary wedge pressure was higher (P less than 0.001) when a third heart sound was detected in patients with aortic stenosis (18.6 mm Hg, vs. 12.1 mm Hg in those without third heart sounds). There was no association between the wedge pressure and third heart sounds in patients with mitral regurgitation. The prevalence of third heart sounds increased with the severity of mitral regurgitation. CONCLUSIONS: In patients with mitral regurgitation, third heart sounds are common but do not necessarily reflect left ventricular systolic dysfunction or increased filling pressure. In patients with aortic stenosis, third heart sounds are uncommon but usually indicate the presence of systolic dysfunction and elevated filling pressure.

Adult↗
PubMed1992

Annoyance caused by simultaneous impulse, road-traffic, and aircraft sounds: a quantitative model.

In this study, total annoyance caused by different simultaneous environmental sounds is investigated. In spite of a number of puzzling data in the literature, it is fairly well established that in combinations in which the annoyance of one source is considerably higher than that of another source, total annoyance is equal to the maximum annoyance of the separate sources. For combinations in which both sounds are about equally annoying, total annoyance seems to be higher than the maximum source-specific annoyance. The available data, however, are too rough to model total annoyance in these conditions. The present laboratory studies were therefore designed to explore further possible procedures to quantify total annoyance. Subjects rated the (total) annoyance caused by various combinations of impulse, road-traffic, and aircraft sounds. The results support a simple model which predicts the overall or total rating sound level L(t) for combinations of several types of sounds. Here, L(t) is numerically equal to the A-weighted equivalent sound level L(eq) of road-traffic sound with the same annoyance as caused by the combination of sounds. In the model, the sound exposure caused by the impulse and/or aircraft sounds is first expressed in the L(eq) of equally annoying road-traffic sound. With the help of source-specific dose-effect relationships, this is achieved by adding level-dependent penalties to the L(eq) of the respective sources. Weighted summation of the corrected L(eq)'s of the various sources then results in L(t). An optimal overall fit of the data from two separate experiments was obtained when the weighted summation of the corrected L(eq)'s was performed with the parameter k in k log(sigma 10(corrected L(eq) of source j)/k) set to 15. The standard deviation of the differences between the experimental results and the model predictions with k = 15 was equivalent to the small change in annoyance produced by a 1.5-dB shift in the L(eq) of road-traffic sound. Adoption of k = 15 implies that after correction, two equal L(eq)'s yield a total rating sound level which is 4.5 dB higher than each single-source corrected L(eq).

Adolescent↗
PubMed1995

Processing of prosthetic heart valve sounds for single leg separation classification.

People with serious heart conditions have had their expected life span extended considerably with the development of the prosthetic heart valve especially with the great strides made in valve design. Even though the designs are extremely reliable, the valves are mechanical and operating continuously over a long period; therefore structural failures can occur due to fatigue. In this paper acoustical signal processing techniques developed to process noisy heart valve sounds measured by a sensitive, surface contact microphone are discussed. Measuring heart sounds noninvasively in a noisy environment puts more demands on the signal processing to extract the desired signals from the noise. Heart valve sounds are short-duration (10-20 ms) transients and therefore nonstationary, requiring more sophisticated processing algorithms to achieve the desired signal-to-noise ratios. In this paper the preclassification signal processing is concentrated on exclusively. That is, the signal processing operations performed on the heart valve sounds prior to classification are discussed--a subject that will be developed in a future paper. Efforts are concentrated on the sounds corresponding to the heart valve opening cycle. Valve opening and closing acoustics present additional information about the outlet strut condition--the structural component implicated in valve failure. The importance of the opening sound for single leg separation detection/classification is based on the fact that as the valve opens, the disk passively hits the outlet strut. The opening sounds thus yield direct information about outlet strut condition with minimal amount of disturbance caused by the energy radiated from the disk. Hence the opening sound is a very desirable acoustic signal to extract. Unfortunately, the opening sounds have much lower signal levels relative to the closing sounds and therefore noise plays a more significant role than during the closing event. Because of this it is necessary to screen the sounds for outliers in order to insure a high sensitivity of classification. Because of the sharp resonances appearing in the corresponding spectrum, a parametric processing approach is developed based on an autoregressive model which was selected to characterize the sounds emitted by the Bjork-Shiley convexo-concave (BSCC) valve during opening cycle. First the basic signals and the extraction process used to create an ensemble of heart valve sounds are briefly discussed. Next, a beat monitor capable of rejecting beats that fail to meet an acceptance criteria based on their spectral content is developed.(ABSTRACT TRUNCATED AT 400 WORDS)

Acoustics↗
PubMed1983

Sound speed in pulmonary parenchyma.

The time it takes audible sound waves to travel across a lobe of excised horse lung was measured. Sound speed, which is the slope in the relationship between transit time and distance across the lobe, was estimated by linear regression analysis. Sound-speed estimates for air-filled lungs varied between 25 and 70 m/s, depending on lung volume. These speeds are less than 5% of sound speed in tissue and less than 20% of sound speed in air. Filling the lung with helium or sulfur hexafluoride, whose free-field sound speeds are 970 and 140 m/s, respectively, changed sound speed +/- 10% relative to air filling. Reducing the ambient pressure to 0.1 atm reduced sound speed to 30% of its 1-atm value. Increasing pressure to 7 atm increased sound speed by a factor of 2.6. These results suggest that 1) translobar sound travels through the bulk of the parenchyma and not along airways or blood vessels, and 2) the parenchyma acts as an elastic continuum to audible sound. The speed of sound is given by c = (B/rho)1/2, where B is composite volumetric stiffness of the medium and rho is average density. In the physiologic state B is affected by ambient pressure and percent gas phase. The average density includes both the tissue and gas phases of the parenchyma, so it is dependent on lung volume. These results may be helpful in the quantification of clinical observations of lung sounds.

Animals↗
PubMed1998

Codes for sound-source location in nontonotopic auditory cortex.

We evaluated two hypothetical codes for sound-source location in the auditory cortex. The topographical code assumed that single neurons are selective for particular locations and that sound-source locations are coded by the cortical location of small populations of maximally activated neurons. The distributed code assumed that the responses of individual neurons can carry information about locations throughout 360 degrees of azimuth and that accurate sound localization derives from information that is distributed across large populations of such panoramic neurons. We recorded from single units in the anterior ectosylvian sulcus area (area AES) and in area A2 of alpha-chloralose-anesthetized cats. Results obtained in the two areas were essentially equivalent. Noise bursts were presented from loudspeakers spaced in 20 degrees intervals of azimuth throughout 360 degrees of the horizontal plane. Spike counts of the majority of units were modulated >50% by changes in sound-source azimuth. Nevertheless, sound-source locations that produced greater than half-maximal spike counts often spanned >180 degrees of azimuth. The spatial selectivity of units tended to broaden and, often, to shift in azimuth as sound pressure levels (SPLs) were increased to a moderate level. We sometimes saw systematic changes in spatial tuning along segments of electrode tracks as long as 1.5 mm but such progressions were not evident at higher sound levels. Moderate-level sounds presented anywhere in the contralateral hemifield produced greater than half-maximal activation of nearly all units. These results are not consistent with the hypothesis of a topographic code. We used an artificial-neural-network algorithm to recognize spike patterns and, thereby, infer the locations of sound sources. Network input consisted of spike density functions formed by averages of responses to eight stimulus repetitions. Information carried in the responses of single units permitted reasonable estimates of sound-source locations throughout 360 degrees of azimuth. The most accurate units exhibited median errors in localization of <25 degrees, meaning that the network output fell within 25 degrees of the correct location on half of the trials. Spike patterns tended to vary with stimulus SPL, but level-invariant features of patterns permitted estimates of locations of sound sources that varied through 20-dB ranges. Sound localization based on spike patterns that preserved details of spike timing consistently was more accurate than localization based on spike counts alone. These results support the hypothesis that sound-source locations are represented by a distributed code and that individual neurons are, in effect, panoramic localizers.

Action Potentials↗
PubMed1985

Investigation of genesis of gallop sounds in dogs by quantitative phonocardiography and digital frequency analysis.

Several investigators have noted external gallop sounds to be of higher amplitude than their corresponding internal sounds (S3 and S4). In this study we hoped to determine if S3 and S4 are transmitted in the same manner as S1. In 11 closed-chest dogs, external (apical) and left ventricular pressures and sounds were recorded simultaneously with transducers with identical sensitivity and frequency responses. Volume and pressure overload and positive and negative inotropic drugs were used to generate gallop sounds. Recordings were made in the control state and after the various interventions. S3 and S4 were recorded in 17 experiments each. The amplitude of the external S1 was uniformly higher than that of internal S1 and internal gallop sounds were inconspicuous. With use of Fourier transforms, the gain function was determined by comparing internal to external S1. By inverse transform, the amplitude of the internal gallop sounds was predicted from external sounds. The internal sounds of significant amplitude were predicted in many instances, but the actual recordings showed no conspicuous sounds. The absence of internal gallop sounds of expected amplitude as calculated from the external gallop sounds and the gain function derived from the comparison of internal and external S1 make it very unlikely that external gallop sounds are derived from internal sounds.

Animals↗
PubMed2002

Squeaking with a sliding joint: mechanics and motor control of sound production in palinurid lobsters.

The origin of arthropod sound-producing morphology typically involves modification of two translating body surfaces, such as the legs and thorax. In an unusual structural rearrangement, I show that one lineage of palinurid lobsters lost an antennal joint articulation, which transformed this joint from moving with one degree of freedom into a sliding joint with multiple degrees of freedom. With this sliding joint, 'stick-and-slip' sounds are produced by rubbing the base of each antenna against the antennular plate. To understand the musculo-skeletal changes that occurred during the origin and evolutionary variation of this sound-producing mechanism, I examined joint morphology and antennal muscle anatomy across sound-producing and non-sound-producing palinurids. Plectrum movement and antennal muscle activity were measured in a sound-producing species, Panulirus argus. The promotor muscle pulls the plectrum over the file during sound-producing and non-sound-producing movements; a higher intensity of muscle activity is associated with sound production. The promotor muscle is larger and attaches more medially in sound-producing palinurids than in non-sound producers. In Panulirus argus, each shingle on the file has an additional ridge; in Palinurus elephas, the shingle surfaces are smooth. These differences in shingle surface features suggest variation in the stick-and-slip properties of the system. Translational motion permitted by the sliding joint is necessary for sound production; hence, the construction of a sliding joint is a key modification in the origin of this sound-producing mechanism.

Animal Communication↗
PubMed1988

Joint-sounds in gonoarthrosis--clinical application of phonoarthrography for the knees.

Auscultation is one of the oldest methods of diagnosis. It has been extensively used in examining various organs of the body, but its use for studying joint-sounds is still an unexplored area of research. In our clinic, a new analyzing system has been developed and its clinical application has been practiced since 1980. The joint-sounds are analyzed with a narrow band spectrum analyzer and a computer. The spectrum of background noise is then subtracted from the linear averaged spectrum to obtain the phonoarthrograph. Our study showed that all the joint-sounds exist at a point lower than 3.5 kHz with the majority of them being lower than 2.5 kHz. Therefore, we believe that there are mainly two kinds of joint-sounds, that is, at the low frequency sound level (L type) and at the high frequency sound level (H type). The significance of joint-sounds at the high frequency sound level is unknown but we suggest that it is due to the thickness and the hardness of the articular surface. Next the significance of joint-sounds at the low frequency sound level were investigated. We think that joint-sounds reflect not only on the change of bone but also on something else due to osteoarthrosis. The sounds which are concerned with the changes as seen on the X-ray films exist at the low frequency sound level mainly from 0.5 kHz to 1.0 kHz. We believe that this method is noninvasive and useful for the diagnosis of osteoarthrosis of joints.

Adult↗
PubMed2006

[Heart sound recognition algorithm based on PNN for evaluating cardiac contractility change trend].

This paper discusses the recognition of heart sound for evaluating the cardiac contractility change trend, which includes heart sound samples recorded at different exercise condition. Especially, focused on the recognition of heart sound recorded after high intensity exercise workload. The algorithm proposed consisted of two correlative methods. The first was to recognize heart sound recorded at rest and after low intensity exercise workloads by probabilistic neural network and the second was to recognize heart sound recorded after high intensity exercise workloads based on the characteristic of heart sound. Both methods have two consecutive phases. Firstly, all peaks, including the peaks of both heart sounds and noise, are marked by a repetitive threshold detecting algorithm. Secondly, probabilistic neural network is employed to classify the peaks detected in the first phase into Si, S2, and noise. Finally, the performance of the algorithm was evaluated using 45 digital heart sound recordings including normal and abnormal heart sound, which were recorded at rest and after low intensity exercise workloads, and 28 digital heart sound recordings recorded after high intensity exercise workloads. The results showed that over 94% of heart sound samples were classified and recognized correctly. Moreover, the reasons for the wrong classification, of which omitting and misdetection are two main problems, are also discussed and solutions are proposed. So this method can be improved and refined in following studies. In conclusion, this algorithm is a reliable approach to detect and classify heart sounds, providing a solid basis for further heart sound analysis.

Algorithms↗
PubMed1994

[Lung sound analysis and pulmonary function studies].

Because of technical difficulties, the study of lung sounds has been neglected for the last 200 years since the age of Laennec. However, recent advances in signal processing and in technology have made it possible to record lung sounds routinely at the bedside or in clinical laboratories. Lung sound analysis has many advantages because it is safe, non-invasive, low-cost, and repeatable. Normal lung sounds can be classified into tracheal, bronchial, and alveolar (vesicular) sounds. They are all common in that the origin of the sound is the turbulence in the airways. The most important and convenient way of distinguishing them is the place where they are heard and the difference in intensity in relation to breathing cycle. Alveolar sounds are heard at the bases and are definitely larger during inspiration, while bronchial sounds are heard at the apex, over the sternum and inter-scapular area, and are equal or louder during expiration. The abnormal, or adventitious lung sounds are classified into continuous and discontinuous. Wheezes are most common continuous sounds. However, in patients with stenosis of trachea or major bronchus large continuous sounds often referred to as rhonchi are heard. They are easily heard over the neck and are important clinical signs which nurses and laboratory technicians must be aware of. By the use of adaptive digital filters we can reduce contaminating noises without the use of sound proof rooms. Because of many advantages, the lung sound analysis has a promising future as a method to supplement other pulmonary function studies.

Humans↗
PubMed2006

The neural mechanism associated with the processing of onomatopoeic sounds.

This event-related fMRI study was conducted to examine the blood-oxygen-level-dependent responses to the processing of auditory onomatopoeic sounds. We used a sound categorization task in which the participants heard four types of stimuli: onomatopoeic sounds, nouns (verbal), animal (nonverbal) sounds, and pure tone/noise (control). By discriminating between the categories of target sounds (birds/nonbirds), the nouns resulted in activations in the left anterior superior temporal gyrus (STG), whereas the animal sounds resulted in activations in the bilateral superior temporal sulcus (STS) and the left inferior frontal gyrus (IFG). In contrast, the onomatopoeias activated extensive brain regions, including the left anterior STG, the region from the bilateral STS to the middle temporal gyrus, and the bilateral IFG. The onomatopoeic sounds showed greater activation in the right middle STS than did the nouns and environmental sounds. These results indicate that onomatopoeic sounds are processed by extensive brain regions involved in the processing of both verbal and nonverbal sounds. Thus, we can posit that onomatopoeic sounds can serve as a bridge between nouns and animal sounds. This is the first evidence to demonstrate the way in which onomatopoeic sounds are processed in the human brain.

Acoustic Stimulation↗
PubMed2003

The importance of sound identification training in phonological intervention.

Little is known about the relevance of sound identification training in phonological intervention. Some treatment approaches incorporate sound identification training; others do not. The purpose of the present study was to compare articulatory improvement following treatment with and without sound identification training. Nine preschool children with severe phonological disorders were randomly assigned to 2 groups for the treatment of stimulable sound errors: (a) mixed training with concurrent production and sound identification training and (b) production-only training. Articulatory improvement was evaluated as a function of treatment type and pretraining sound identification scores. No overall difference was found between the 2 treatment types except for sounds that had been poorly identified. Articulatory errors with low identification scores made greater progress after receiving mixed training with both production and sound identification training. For error sounds receiving production training, significant relationships were found between both pre- and posttraining identification scores and articulatory improvement, suggesting (a) that perception of error sounds prior to treatment may affect degree of improvement and (b) that production training may improve perception of error sounds. Different views exist with regard to the targeting of stimulable error sounds for treatment. Results of the present study suggest that sound identification in addition to stimulability may be an important consideration in target selection as well as treatment mode.

Articulation Disorders↗
PubMedDate not supplied

Mandibular incisor position for English consonant sounds.

PURPOSE: The purpose of this study was to describe the mandibular incisor positions for the 24 consonant sounds of the English language. Further aims were to determine if the incisor format for each sound is affected by its position in a word, or by combination with an open or closed vowel. MATERIALS AND METHODS: A total of 30 young adult subjects had their incisal positions determined using an electrognathographic technique during performance of a number of speech tests. RESULTS: The mean values of the 24 consonants, in the vertical direction, showed a range from the intercuspal position of 2.5 mm for a sibilant sound to 11.7 mm for the /H/ sound, and an anteroposterior range of 1.4 mm anterior for a sibilant sound to 1.8 mm posterior for the /M/ sound. The range in the mean lateral dimension was always less than 1 mm on either side of the midline. The placement of a sound in the initial or final position in a word had no effect on the incisal position. The degree of vertical opening was significantly greater for 8 of the consonant sounds when in combination with an open vowel sound. The anteroposterior and lateral positions were unaffected by vowel association. CONCLUSION: The incisor position for consonant sounds is unaffected by initial or final word placement. Some consonant sound positions are affected by combination with an open or closed vowel sound. Sibilant sounds produced a clinically acceptable measure of the most superior and anterior speaking positions in all subjects.

Adult↗