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PubMed1982

Lateral eye movements to verbal and spatial questions as a function of questioner location.

Fifty right-handed females thought about answer to verbal and spatial reasoning questions asked by a questioner seated either in front of or behind them. Ss in the questioner-in-front condition predominantly exhibited left lateral eye movements regardless of the question type, while the lateral eye movements of the questioner-in back Ss showed no directional trend in response to either question type. S's self-reported anxiety was not associated with lateral eye movements in either questioner-location condition.

Adult↗
PubMed1990

Aftereffect arising from unidirectional change of sound level in a tone: frequency specificity with a complex adaptor.

Subjects adapted to square-wave adaptors, stimuli containing odd harmonics of the fundamental, and, to provide baseline data, sinusoidal adaptors matching the square-wave's fundamental. Nulls were obtained for various frequencies of the test stimulus. At any given frequency, the baseline null was subtracted from the null for square-wave adaptation. These corrected nulls indicated frequency-specific aftereffects at the third and fifth harmonics. The evidence is consistent with previous attempts to link the aftereffect of changing sound level in a tone with the auditory movement aftereffect because the latter may also show frequency specificity.

Adult↗
PubMed1995

The influence of onset sound level of test stimulus on reported magnitude of changing-loudness aftereffects.

An increasing-loudness aftereffect follows adaptation to a tone of decreasing sound level; a decreasing-loudness aftereffect follows adaptation to a tone of increasing sound level. Contrary to the belief that sensory processing contributes to these changing-loudness aftereffects, evidence suggests that onset sound level of test stimulus may have little influence on reported aftereffects. This was tested formally in the present study. Adapting stimuli and test stimuli all employed 1-kHz sinusoidal carriers: Three onset sound levels of test stimuli were well within the range of sound levels encompassed by adapting stimuli; a fourth was set at the highest value of this range. Consistent with previous evidence, substantial aftereffects were reported for all the midrange onset sound levels, with little difference across onset sound levels. However, for the high-range onset sound level, reported aftereffects were severely attenuated. Sensory processing can be invoked by supposing that aftereffect mechanisms "tap" neural activity that encodes adapting sound levels.

Humans↗
PubMed2001

Audiological assessment of unilateral deafness.

Unilateral deafness constitute medical (aetiological diagnosis, treatment, hearing aid fitting) and social problems (no certification of disability). Following audiological examinations were performed in the study: pure tone audiometry (PTA), impedance audiometry, auditory brainstem responses (ABR), otoacoustic emissions (OAE), as well as balance, taste, examinations and electric sensitivity of the acoustic nerve. In cases of tinnitus the parameters of its character were done. All of our patients underwent X-ray investigations, i.e. ear X-ray by Schüller and Stenvers methods, computerized tomography or magnetic resonance imaging. In some cases phoniatric and logopaedic examinations were performed. For aetiological diagnosis electrophoresis and immunological test (IgG and IgM against mumps) were carried out. The results were presented in two groups of patients with sudden and those of long lasting progressive unilateral deafness. Some of the patients were pharmacologically treated before the evaluation. It is concluded that the statistic analysis could be a basis for the management and prognosis of the unilateral deafness.

Adolescent↗
PubMed1999

Measures of the binaural interaction component in human auditory brainstem response using objective detection criteria.

The occurrence of binaural interaction in humans has been demonstrated using auditory brainstem response (ABR). A distinctly binaural potential, beta, is derived by subtracting the ABR recording evoked by binaural clicks from the monaural aggregate, i.e., the sum of the two corresponding ABR recordings evoked by monaural clicks. However, few clinical data are available, possibly because the beta-wave is considered an elusive response due to a low signal-to-noise-ratio. In the present study, beta-wave latency, amplitude and area were evaluated for 10 subjects with normal hearing using automatic analysis and averaging based on a large number of stimulations. The efficacy of the beta-wave measures was assessed using different stimulus rates, as binaural interaction is known to decrease with increasing stimulus rate. It was found that the beta-wave given by automatic analysis demonstrated known characteristics of binaural interaction in human ABR, i.e. the absence of binaural interaction during wave III, significant binaural interaction during wave V and a significant decrease in binaural interaction when the stimulus rate was increased. These findings suggest that a beta-wave in the binaural difference waveform can be detected and quantified using automatic analysis, thus it is suitable for clinical studies, at least for patients with normal hearing thresholds.

Adult↗
PubMed1995

Ventriloquist effect reinstates responsiveness to auditory stimuli in the 'ignored' space in patients with hemispatial neglect.

We examined 6 patients with robust visual neglect following right hemisphere damage. All of them had signs of auditory neglect as documented by the inferior identification of syllables delivered through a loudspeaker on the left side. When the same stimuli on the left were administered in the presence of a fictitious source of sound (a dummy loudspeaker) visible in the homolesional space, a significant increase in the identification score of sounds was obtained (the "ventriloquist" effect). The result is in keeping with a notion of a strong coupling between auditory and visual systems. The effect is attributed to the activation by the fictitious source of sound of the audio-visual map in the left hemisphere. We draw attention to the possibility that loss of awareness of auditory input may arise due to the disconnection of the visual input from the audio-visual template.

Adult↗
PubMed2002

Head-centred meridian effect on auditory spatial attention orienting.

Six experiments examined the issue of whether one single system or separate systems underlie visual and auditory orienting of spatial attention. When auditory targets were used, reaction times were slower on trials in which cued and target locations were at opposite sides of the vertical head-centred meridian than on trials in which cued and target locations were at opposite sides of the vertical visual meridian or were not separated by any meridian. The head-centred meridian effect for auditory stimuli was apparent when targets were cued by either visual (Experiments 2, 3, and 6) or auditory cues (Experiment 5). Also, the head-centred meridian effect was found when targets were delivered either through headphones (Experiments 2, 3, and 5) or external loud-speakers (Experiment 6). Conversely, participants showed a visual meridian effect when they were required to respond to visual targets (Experiment 4). These results strongly suggest that auditory and visual spatial attention systems are indeed separate, as far as endogenous orienting is concerned.

Adult↗
PubMed2006

Effects of unit formation on the perception of a changing sound.

The effects of subunit formation on adult listeners' ability to notice changes in a continuous spectral gradient of sound were studied. Results of this experiment support the idea that the auditory system processes information differently within a unit, and that this processing does not occur unless the perceptual system detects unit boundaries. In this experiment, silences were inserted into a continuously changing sound to cause the formation of short units. Listeners noticed the change earlier in conditions with silences inserted than in to conditions where the transition was either unbroken or broken by loud noise bursts. Results are discussed in terms of two processes, one that accentuates stimulus properties present at moments of onset and offset, and a second that uses onsets and offsets to signal the beginnings and ends of units and reduces the change perceived within units.

Auditory Perception↗
PubMed2006

Action-feature integration blinds to feature-overlapping perceptual events: evidence from manual and vocal actions.

Previous studies showed that the identification of a left- or right-pointing arrowhead is impaired when it appears while planning and executing a spatially compatible left or right keypress (Müsseler & Hommel, 1997a). We attribute this effect to stimulus processing and action control operating on the same feature codes so that, once a code is integrated in an action plan, it is less available for perceptual processing. In three pairs of experiments we tested the generality of this account by using stimulus-response combinations other than arrows and manual keypresses. Planning manual left-right keypressing actions impaired the identification of spatially corresponding arrows but not of words with congruent meaning. On the contrary, planning to say "left" or "right" impaired the identification of corresponding spatial words but not of congruent arrows. Thus, as the feature-integration approach suggests, stimulus identification is impaired only with overlap of perceptual or perceptually derived stimulus and response features while mere semantic congruence is insufficient.

Distance Perception↗
PubMed1981

Effects of age on acquisition and maintenance of a location discrimination in rats.

Twelve-and thirty-month old Sprague Dawley rats were trained in an auditory discrimination using a discrete trial procedure with food as the reinforcer. Two thirty-month an two twelve-month animals acquired the discrimination in one trail. The asymptotic level of correct responding was lower for the old animals and this was attributed to changes in auditory threshold with age. The thirty-month animals gave more intertrial interval responses than the twelve-month animals. There was no difference in the average response latency for the two age groups.

Aging↗
PubMed2006

Estimating receptive fields in the presence of spike-time jitter.

Neurons in sensory systems are commonly characterized by their receptive fields. These are experimentally often obtained by reverse-correlation analyses, for example, by calculating the spike-triggered average. The reverse-correlation approach, however, generally assumes a fixed temporal relation between spike-generating stimulus features and measured spikes. Temporal jitter of spikes will therefore distort the estimated receptive fields. Here, a novel extension of widely used reverse-correlation techniques (spike-triggered average as well as spike-triggered covariance) is presented that allows accurate measurements of receptive fields even in the presence of considerable spike-time jitter. It is shown that the method correctly recovers the receptive fields from simulated spike trains. When applied to recordings from auditory receptor cells of locusts, a considerable sharpening of receptive fields as compared to standard spike-triggered averages is observed. In addition, the multiple filters that are obtained from a conventional spike-triggered covariance analysis of these data can be collapsed into a single component if spike jitter is accounted for. Finally, it is shown how further effects on spike timing, such as systematic shifts in spike latency, can be included in the approach.

Acoustic Stimulation↗
PubMedDate not supplied

Visualization tools for blind people using multiple modalities.

PURPOSE: There are many problems when blind people need to access visualizations such as graphs and tables. Current speech or raised-paper technology does not provide a good solution. Our approach is to use non-speech sounds and haptics to allow a richer and more flexible form of access to graphs and tables. METHOD: Two experiments are reported that test out designs for both sound and haptic graph solutions. In the audio case a standard speech interface is compared to one with non-speech sounds added. The haptic experiment compares two different graph designs to see which was the most effective. RESULTS: Our results for the sound graphs showed a significant decrease in subjective workload, reduced time taken to complete tasks and reduced errors as compared to a standard speech interface. For the haptic graphs reductions in workload and some of the problems that can occur when using such graphs are shown. CONCLUSIONS: Using non-speech sound and haptics can significantly improve interaction with visualizations such as graphs. This multimodal approach makes the most of the senses our users have to provide access to information in more flexible ways.

Blindness↗
PubMed2005

The head-centered meridian effect: auditory attention orienting in conditions of impaired visuo-spatial information.

This paper examines the characteristics of spatial attention orienting in situations of visual impairment. Two groups of subjects, respectively schizophrenic and blind, with different degrees of visual spatial information impairment, were tested. In Experiment 1, the schizophrenic subjects were instructed to detect an auditory target, which was preceded by a visual cue. The cue could appear in the same location as the target, separated from it respectively by the vertical visual meridian (VM), the vertical head-centered meridian (HCM) or another meridian. Similarly to normal subjects tested with the same paradigm (Ferlazzo, Couyoumdjian, Padovani, and Olivetti Belardinelli, 2002), schizophrenic subjects showed slower reactions times (RTs) when cued, and when the target locations were on the opposite sides of the HCM. This HCM effect strengthens the assumption that different auditory and visual spatial maps underlie the representation of attention orienting mechanisms. In Experiment 2, blind subjects were asked to detect an auditory target, which had been preceded by an auditory cue, while staring at an imaginary point. The point was located either to the left or to the right, in order to control for ocular movements and maintain the dissociation between the HCM and the VM. Differences between crossing and no-crossing conditions of HCM were not found. Therefore it is possible to consider the HCM effect as a consequence of the interaction between visual and auditory modalities. Related theoretical issues are also discussed.

Adolescent↗
PubMed1991

A computer model of auditory stream segregation.

A computer model is described which simulates some aspects of auditory stream segregation. The model emphasizes the explanatory power of simple physiological principles operating at a peripheral rather than a central level. The model consists of a multi-channel bandpass-filter bank with a "noisy" output and an attentional mechanism that responds selectively to the channel with the greatest activity. A "leaky integration" principle allows channel excitation to accumulate and dissipate over time. The model produces similar results to two experimental demonstrations of streaming phenomena, which are presented in detail. These results are discussed in terms of the "emergent properties" of a system governed by simple physiological principles. As such the model is contrasted with higher-level Gestalt explanations of the same phenomena while accepting that they may constitute complementary kinds of explanation.

Attention↗
PubMed2004

The Speech, Spatial and Qualities of Hearing Scale (SSQ).

The Speech, Spatial and Qualities of Hearing Scale (SSQ) is designed to measure a range of hearing disabilities across several domains. Particular attention is given to hearing speech in a variety of competing contexts, and to the directional, distance and movement components of spatial hearing. In addition, the abilities both to segregate sounds and to attend to simultaneous speech streams are assessed, reflecting the reality of hearing in the everyday world. Qualities of hearing experience include ease of listening, and the naturalness, clarity and identifiability of different speakers, different musical pieces and instruments, and different everyday sounds. Application of the SSQ to 153 new clinic clients prior to hearing aid fitting showed that the greatest difficulty was experienced with simultaneous speech streams, ease of listening, listening in groups and in noise, and judging distance and movement. SSQ ratings were compared with an independent measure of handicap. After differences in hearing level were controlled for, it was found that identification, attention and effort problems, as well as spatial hearing problems, feature prominently in the disability handicap relationship,. along with certain features of speech hearing. The results implicate aspects of temporal and spatial dynamics of hearing disability in the experience of handicap. The SSQ shows promise as an instrument for evaluating interventions of various kinds, particularly (but not exclusively) those that implicate binaural function.

Aged↗
PubMed2006

Effects of bilateral versus unilateral hearing aid fitting on abilities measured by the Speech, Spatial, and Qualities of Hearing Scale (SSQ).

The Speech, Spatial and Qualities of Hearing Scale (Gatehouse & Noble, 2004) was applied to three independent clinical groups: 144 people prior to being fitted with amplification; 118 people with six months experience with unilateral amplification; and 42 people with six months experience with bilateral amplification. For traditional speech hearing contexts (one-on-one, in groups, in quiet, in noise) there was benefit with one aid, and no further benefit with two. By contrast, hearing speech in demanding contexts (divided or rapidly switching attention) showed benefit with one aid and further benefit with two. In the spatial domain, directional hearing showed some benefit with one hearing aid, and particular further benefit in distance and movement discrimination from fitting with two. There was some benefit from unilateral fitting for elements of the qualities domains (clarity, naturalness, recognisability, segregation of sounds), with no consistent sign of further benefit from two. Bilateral fitting added benefit with respect to listening effort. Two hearing aids offer advantage in demanding and dynamic contexts; these contexts are argued as significant in the maintenance of social competence and emotional wellbeing. The present results go toward establishing the real-world advantages of bilateral hearing aid fitting and suggest that previous, inconclusive clinical findings reflect inquiry limited to more traditional areas of hearing function.

Aged↗
PubMed2006

The listening in Spatialized Noise test: normative data for children.

The Listening in Spatialized Noise test (LISN) produces a three-dimensional auditory environment under headphones, using only a PC and an audiometer, and was designed to provide an ecologically valid assessment of auditory figure-ground skills in children. The listener is required to indicate the intelligibility level of a story presented at 0 degree azimuth, in the presence of distracter sentences simultaneously presented at either 0 degree or +/- 90 degrees azimuth. Various measures assess the extent to which either spatial, vocal, or spatial and vocal cues combined, increase a listener's ability to comprehend the story, without being affected by differences between participants in variables such as linguistic skills. There was a trend of improved performance with increasing age for 48 normally hearing seven-, eight-, and nine-year-olds, and sixteen adults. Whereas some significant differences were found between adults and children, there were no significant differences in performance between the seven-, eight-, and nine-year-olds on any measure, and no significant gender or practice effects were observed. Future studies on children with suspected auditory processing disorder were considered warranted.

Adult↗