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At least 19 recordsLinked to original sources
PubMed2004

[Clinical psychoacoustics can support an objective diagnosis of schizophrenia].

This article deals with a new branch of research in psychiatry focusing upon schizophrenia in the first hand. Methods of investigating psychoacoustic aberrations in this disease have been developed during the last twenty years at our laboratory; Unit of Clinical psychoacoustics, Division of Psychiatry, Dept of Clinical Neuroscience, Lund University (www.psykiatr.lu.se/psykoaclab). Schizophrenic persons show dysfunctions at the psychophysiological level as displayed by many psychoacoustic mechanisms such as streaming, restoration and contralateral induction of sounds. These dysfunctions may influence general cognitive and perceptual processes and partly explain clinically observed symptoms of the disease. Further investigations on the efforts to elucidate normal functioning of the psychoacoustic processes by functional magnetic resonance imaging, auditory brainstem response and via animal models are described. One immediate aim of all the studies is to be able to demonstrate objective measurements of the schizophrenic aberrations using psychoacoustic tests. This would help supporting the diagnosis, setting early diagnosis or guide therapeutic decisions.

Animals↗
PubMed2006

Influence of musical and psychoacoustical training on pitch discrimination.

This study compared the influence of musical and psychoacoustical training on auditory pitch discrimination abilities. In a first experiment, pitch discrimination thresholds for pure and complex tones were measured in 30 classical musicians and 30 non-musicians, none of whom had prior psychoacoustical training. The non-musicians' mean thresholds were more than six times larger than those of the classical musicians initially, and still about four times larger after 2h of training using an adaptive two-interval forced-choice procedure; this difference is two to three times larger than suggested by previous studies. The musicians' thresholds were close to those measured in earlier psychoacoustical studies using highly trained listeners, and showed little improvement with training; this suggests that classical musical training can lead to optimal or nearly optimal pitch discrimination performance. A second experiment was performed to determine how much additional training was required for the non-musicians to obtain thresholds as low as those of the classical musicians from experiment 1. Eight new non-musicians with no prior training practiced the frequency discrimination task for a total of 14 h. It took between 4 and 8h of training for their thresholds to become as small as those measured in the classical musicians from experiment 1. These findings supplement and qualify earlier data in the literature regarding the respective influence of musical and psychoacoustical training on pitch discrimination performance.

Acoustic Stimulation↗
PubMed1995

"Say-stay" identification and psychoacoustic performance of hearing-impaired listeners.

Controversy exists over the extent to which psychoacoustic abilities explain speech perception. The present study addressed this issue by assessing the contribution of psychoacoustic abilities to speech identification by hearing-impaired listeners. Speech stimuli and nonspeech analogs were presented to normal-hearing and hearing-impaired listeners with varying degrees of hearing loss. Phonemic judgments for synthetic versions of "say-stay" stimuli were evaluated as a function of first formant onset frequency and of silence duration between the /s/ noise and the vocalic portion. Three psychoacoustic measures were obtained: glide onset frequency discrimination, gap detection in noise, and gap detection in speechlike composite signals. Although the resulting difference limens increased with increasing hearing loss, the acoustic cues to the speech contrast were available to all listeners. Nonetheless, the response patterns to the speech stimuli varied among groups in a manner that was not explained by the psychoacoustic results. Thus, although hearing-impaired listeners were able to detect and discriminate essential acoustic cues for speech, the perceptual organization of speech stimuli appeared to differ with degree of loss. Alternative explanations for the findings are considered, including the possible effect of hearing loss on auditory/linguistic experience.

Adolescent↗
PubMed2005

Psychoacoustic quantification of mechanical heart valve noise.

BACKGROUND AND AIM OF THE STUDY: Mechanical heart valves produce short clicking sounds during closure. These closing sounds are annoying for some patients and their partners by causing sleeping disorders or social embarrassment. Various methods for measuring the sounds have been developed both in vitro and in vivo using calculation of A-weighted sound pressure level or loudness according to ISO 532 B. The study aim was to evaluate the relevance of different psychoacoustic parameters in the evaluation of closing sounds. METHODS: Closing sounds were recorded from patients with ATS valves (n = 13), On-X valves (n = 18) and St. Jude Medical heart valve prostheses (n = 16). The sounds were recorded 5 cm above the chest of patients in a supine position, in a sound-insulated chamber. The mean peak values of loudness and sharpness were calculated and used to determine the psychoacoustic annoyance using a modification of the Widmann formula. This was verified by a listening test for ranking closing sounds of different level and sharpness by annoyance. RESULTS: There was no statistically significant independence between loudness difference or psychoacoustic annoyance difference and agreement among the test persons. For the valves, loudness ranged from 0.07 to 2.57 sone, and the psychoacoustic annoyance from 0.1 to 5.4. CONCLUSION: The results of this study showed that both sharpness and loudness have a significant influence on annoyance from closing sounds from mechanical heart valves, and indicated that the substantial variation in the parameters may be due to individual patient physiology.

Adult↗
PubMed2002

Temporal resolution in young and elderly subjects as measured by mismatch negativity and a psychoacoustic gap detection task.

OBJECTIVES: The speech understanding difficulties of elderly persons with age-related hearing loss may be related in part to reduced auditory temporal resolution. To investigate the effects of aging on temporal resolution, the electrophysiological and psychoacoustic detection thresholds for a very short silent gap within a pure tone were determined, and the relation between the two test results was examined. METHODS: Behavioral gap detection thresholds were determined in 10 young and 10 elderly normally hearing subjects using an adaptive test procedure. To elicit mismatch negativity (MMN), deviant stimuli with gap durations varying from 6 to 24 ms in 3 ms steps were presented in separate test blocks. RESULTS: There were no significant differences in the psychoacoustic gap detection thresholds between young and elderly subjects. In contrast, longer gaps were needed to elicit MMN in elderly subjects. They also had significantly reduced MMN peak amplitudes, increased MMN peak latencies, a significantly smaller P2 amplitude and longer P2 latency in their responses to the standard stimulus when compared to the same measures in young subjects. CONCLUSIONS: Processing of basic temporal stimulus features in elderly subjects is considerably more reduced at the preattentive level (as indicated by MMN), than when attention is directed to the task (as indicated by the psychoacoustic results).

Acoustic Stimulation↗
PubMed2005

Inferring basilar-membrane motion from tone-burst otoacoustic emissions and psychoacoustic measurements.

The amplitude of otoacoustic emissions, which arise on the basilar membrane, is assumed to be proportional to basilar-membrane motion. It should then be possible to assess basilar-membrane motion on the basis of otoacoustic emissions. The present study provides support for this possibility by comparing basilar-membrane motion inferred from emissions to that inferred from psychoacoustic measures. Three psychoacoustic measurements believed to be associated with basilar-membrane motion were investigated: (1) pulsation threshold; (2) loudness functions derived from temporal integration; and (3) loudness functions derived from loudness matches between pure tones and multitone complexes. Results of the psychoacoustic measurements and of the tone-burst otoacoustic emissions led to very similar estimations of basilar-membrane motion. Accordingly, emissions could serve as an excellent tool--one that is objective, noninvasive, and rapid--for estimating relative basilar-membrane motion.

Acoustic Stimulation↗
PubMed2001

Auditory edge detection: a neural model for physiological and psychoacoustical responses to amplitude transients.

Primary segmentation of visual scenes is based on spatiotemporal edges that are presumably detected by neurons throughout the visual system. In contrast, the way in which the auditory system decomposes complex auditory scenes is substantially less clear. There is diverse physiological and psychophysical evidence for the sensitivity of the auditory system to amplitude transients, which can be considered as a partial analogue to visual spatiotemporal edges. However, there is currently no theoretical framework in which these phenomena can be associated or related to the perceptual task of auditory source segregation. We propose a neural model for an auditory temporal edge detector, whose underlying principles are similar to classical visual edge detector models. Our main result is that this model reproduces published physiological responses to amplitude transients collected at multiple levels of the auditory pathways using a variety of experimental procedures. Moreover, the model successfully predicts physiological responses to a new set of amplitude transients, collected in cat primary auditory cortex and medial geniculate body. Additionally, the model reproduces several published psychoacoustical responses to amplitude transients as well as the psychoacoustical data for amplitude edge detection reported here for the first time. These results support the hypothesis that the response of auditory neurons to amplitude transients is the correlate of psychoacoustical edge detection.

Animals↗
PubMed2000

Psychoacoustic measures of tinnitus.

This report reviews research from the 1930s to the present that has extended our understanding by investigating the characteristics of tinnitus that can be studied using psychoacoustic techniques. Studies of tinnitus masking and residual inhibition began in the 1970s, leading to the therapeutic use of tinnitus masking and a consequent increase in research devoted to tinnitus measurement. In 1981, the CIBA Foundation symposium on tinnitus advocated general adoption of four tinnitus measures: (1) pitch, (2) loudness, (3) maskability, and (4) residual inhibition. Since then, psychoacoustic research into all four topics has proliferated, yielding many valuable insights and controversies concerning the details of measurement techniques. A consensus has emerged that neither the loudness nor other psychoacoustic measures of tinnitus bear a consistent relation to the severity or perceived loudness of tinnitus. Nevertheless, quantification is needed in clinical trials of proposed treatments and in a variety of other types of tinnitus research. Standardization of techniques for specifying the acoustic parameters of tinnitus thus continues to be an important research goal.

Humans↗
PubMed1989

Psychoacoustic abilities of subjects with unilateral and bilateral cochlear hearing impairments and their relationship to the ability to understand speech.

This paper is concerned with deficits in the ability to distinguish sounds, which accompany hearing loss of cochlear origin, and with the relationship of those deficits to the ability to understand speech in quiet and in background noise. Nine subjects with moderate unilateral cochlear hearing loss and 6 with moderate bilateral cochlear hearing loss took part in a series of psychoacoustic and speech perception tests. The impaired ears showed deficits in several of the psychoacoustic tests, including: detection of temporal gaps in bands of noise; frequency discrimination of pure tones; frequency discrimination of complex tones; and frequency selectivity as measured by the masking of tones by notched noise. The impaired ears showed near-normal performance in the detection of changes in intensity and for detecting temporal gaps in sinusoidal signals. Speech reception thresholds (SRTs--defined as the level of speech required for 50% intelligibility) were measured both in quiet and in speech-shaped noise, and were invariably higher for the impaired than for the normal ears. Correlational analysis, principal-components analysis and multiple-regression analysis were used to explore the relationships between the psychoacoustic measures and the SRTs. The results suggest that SRTs in quiet are determined primarily by absolute thresholds as measured by the pure-tone audiogram. SRTs in noise are related more to supra-threshold discrimination abilities, such as the detection of temporal gaps in noise and the frequency discrimination of pure and complex tones, and to age. Possible clinical applications of the results are briefly discussed.

Adult↗
PubMed2003

Contribution of psychoacoustics and neuroaudiology in revealing correlation of mental disorders with central auditory processing disorders.

BACKGROUND: Psychoacoustics is a fascinating developing field concerned with the evaluation of the hearing sensation as an outcome of a sound or speech stimulus. Neuroaudiology with electrophysiologic testing, records the electrical activity of the auditory pathways, extending from the 8th cranial nerve up to the cortical auditory centers as a result of external auditory stimuli. Central Auditory Processing Disorders may co-exist with mental disorders and complicate diagnosis and outcome. DESIGN: A MEDLINE search was conducted to search for papers concerning the association between Central Auditory Processing Disorders and mental disorders. The research focused on the diagnostic methods providing the inter-connection of various mental disorders and central auditory deficits. MEASUREMENTS AND MAIN RESULTS: The medline research revealed 564 papers when using the keywords 'auditory deficits' and 'mental disorders'. 79 papers were referring specifically to Central Auditory Processing Disorders in connection with mental disorders. 175 papers were related to Schizophrenia, 126 to learning disabilities, 29 to Parkinson's disease, 88 to dyslexia and 39 to Alzheimer's disease. Assessment of the Central Auditory System is carried out through a great variety of tests that fall into two main categories: psychoacoustic and electrophysiologic testing. Different specialties are involved in the diagnosis and management of Central Auditory Processing Disorders as well as the mental disorders that may co-exist with them. As a result it is essential that they are all aware of the possibilities in diagnostic procedures. CONCLUSIONS: Considerable evidence exists that mental disorders may correlate with CAPD and this correlation could be revealed through psychoacoustics and neuroaudiology. Mental disorders that relate to Central Auditory Processing Disorders are: Schizophrenia, attention deficit disorders, Alzheimer's disease, learning disabilities, dyslexia, depression, auditory hallucinations, Parkinson's disease, alcoholism, anorexia and childhood mental retardation. Clinical awareness should be high in order for doctors of the two specialties, psychiatry and otorhinolaryngology-audiology to collaborate.

Journal Article↗
PubMedDate not supplied

A multivariate strategy for prediction of psychoacoustic performance from electroacoustic characteristics of hearing aids.

Sentence length psychoacoustic material was processed through 16 hearing aids and presented to 220 listeners. Twenty-nine indices of electroacoustic performance were abstracted from a testing program under laboratory conditions. Through a multivariate statistical strategy, psychoacoustic achievement was shown to be positively correlated to and could be predicted by a knowledge of white noise gain, bandwidth below and above 1 kHz, frequency response regularity, and transiet distortion (multiple R = 0.77; F = 2.04; df = 5,10). It was concluded that a multivariate statistical tactic, when used with discretion, can be a useful and powerful tool to predict psychoacoustic performance from a knowledge of hearing aid electroacoustic characteristics.

Amplifiers, Electronic↗
PubMed2003

[Examination of binaural signal processing in normally hearing subjects using electrophysiological and psychoacoustical measurements].

BACKGROUND AND OBJECTIVE: At present, only a small number of validated, clinically usable methods for the assessment of binaural hearing capabilities exist. A proposed electrophysiological measure is the registration of the brainstem-based binaural difference potentials (BDP). PATIENTS/METHODS: The BDP is calculated as the difference between the binaurally evoked registration and the sum of the two monaural registrations. Detection and stability of the BDP were examined in 24 normally hearing adults within the framework of conventional registration of auditory brainstem responses. Furthermore, the influence of interaural time differences (ITD) on the BDP was determined. In addition, lateralization of the subjects was assessed using a psychoacoustical method. RESULTS: The components of the BDP could be detected in almost all of the subjects. Moreover, they showed sufficient test-retest reliability. The impact of ITD,which causes lateralization of the stimulus,was clearly detectable for the latencies and the amplitudes of the BDP. CONCLUSIONS: Binaural difference potentials, which are easily and reliably detectable reveal a relationship to the outcome of psychoacoustical assessment of lateralization and have the potential to provide a measure for binaural hearing capacity.

Acoustic Stimulation↗
PubMed1980

The time resolution of changes in short duration signal changes-psychoacoustical and electrophysiological studies.

Besides intensity and frequency analysis, time resolution ability is an important factor of auditory processing. Psychoacoustical and electrophysiological studies of peripheral and central time analysis phenomena have been performed to obtain more information as to this ability of the hearing organ. By presenting bursts of noise including short-duration intensity or frequency changes we analysed the sensation levels of these short-lasting changes in signal structure. In normally hearing subjects we derived time constants between 3 and 50 ms depending on the degree of intensity or frequency change. The re sults of psychoacoustical and electrophysiological measurements are compared. Age-dependent changes and other abnormalities are discussed.

Cochlea↗
PubMed1981

Improving psychoacoustical tuning curves.

The probe signal in psychoacoustical tuning curves stimulates more than one neuron, even when presented at low levels. The subject can "listen" to neurons with characteristic frequencies away from the nominal probe frequency and optimize performance. This "off-frequency listening" can account for much of the discrepancy in the sharpness of tuning between psychoacoustical tuning curves obtained in forward masking and neurophysiological tuning curves. By adding a band-reject noise, centred on the probe frequency, to limit off-frequency listening, results in close agreement with the neurophysiological data can be produced.

Acoustic Stimulation↗
PubMed1988

Comparative psychoacoustics.

Psychophysical data on unspecialized mammals commonly used in auditory research were compiled from the literature, and an attempt was made to compare the hearing capacities of these species with man. Binaural hearing and sound localization were not considered. The most complete psychoacoustic data exist for chinchilla, cat, various primates, and the mouse. The existing data include audiograms, frequency and intensity discrimination thresholds, critical masking ratios, critical bandwidths, temporal summation functions at threshold, psychophysical tuning curves, gap detection thresholds, temporal modulation transfer functions, temporal discriminations, and auditory filter shapes. In general, the qualitative forms of most all psychoacoustic functions for these mammals are similar to those for man, and there is little reason to believe that the mechanisms underlying these capacities are different across mammals. Although the discriminative capacities of humans are generally more acute than those of non-humans, the database on the capacities of non-humans is not yet sufficient for systematic comparisons across species to be made with confidence.

Animals↗
PubMedDate not supplied

Psychoacoustic and electrophysiologic effects of partial eighth nerve damage.

The authors present psychoacoustic and electrophysiologic data concerning a patient with partial damage to the auditory nerve, presumably from a dilated arterial vessel. The lesion was described and documented during neurosurgery for vestibular nerve decompression. Pure tone thresholds, psychoacoustical tuning curves, speech reception ability for spondaic words, maximum word recognition performance for monosyllabic NU-6 word lists, and performance on the synthetic sentence identification test in the ipsilateral and contralateral competing message modalities were normal. Findings consistent with eighth nerve dysfunction, absent contralateral acoustic reflexes, absent or unrecognizable early evoked potentials occurring in the first 10 msec, brainstem auditory evoked potentials (BAEPs), and slight rollover of the performance intensity function for monosyllabic words were obtained on the involved side. In spite of the grossly abnormal BAEPs, two late, presumably cortical, auditory evoked potential components, which occur in the 60 to 250-msec range--vertex potential and T complex--were present and normal. The findings indicate that the perceptual processes needed for speech reception and recognition and for the appearance of later, presumably cortical-evoked potentials can be preserved despite partial damage to the auditory nerve.

Adult↗
PubMed2002

Psychoacoustics of normal and impaired hearing.

Recent developments in the field of psychoacoustics are presented, focusing on areas which have application in the diagnosis and understanding of impaired hearing. Cochlear hearing loss often results in a loss of the compressive non-linearity that operates in normal ears; this loss is probably the main cause of loudness recruitment. Forward masking can be used as a tool to assess the strength of cochlear compression in human listeners. Hearing impairment can sometimes be associated with complete loss of function of inner hair cells over a certain region of the cochlea, resulting in a 'dead region'. Two psychoacoustic methods for detecting dead regions and defining their limits are described. The implications of the results for fitting hearing aids are discussed. Finally, the effect of cochlear hearing loss on the perception of rapid sequences of sounds (stream segregation) is described.

Auditory Perception↗
PubMed2003

Transient emission suppression tuning curve attributes in relation to psychoacoustic threshold.

Ipsilateral suppression characteristics of transiently evoked otoacoustic emissions (TEOAEs) are described in relation to psychoacoustic threshold at 4000 Hz and the presence or absence of spontaneous otoacoustic emissions in 41 adults with normal hearing. TEOAE amplitudes were measured in response to 4000-Hz tonebursts presented in linear blocks at 40 and 50 dB SPL while puretone suppressors were introduced at a variety of frequencies and levels ipsilateral to and simultaneously with the tonebursts. Suppressors close to the toneburst frequency were most effective in decreasing the amplitude of the TEOAEs, while those more remote in frequency required significantly greater intensity for a similar amount of suppression. Consequently, characteristic tuning curve shapes were obtained. Tuning-curve tip levels were closely associated with the level of the toneburst and tip frequencies occurred at or above the toneburst frequency. Tuning-curve widths (Q10), however, varied significantly across subjects with similar psychoacoustic thresholds in quiet determined by a two-alternative forced-choice method. The results suggest that a portion of that variability may be explained by the presence or absence of spontaneous otoacoustic emissions in an individual ear.

Acoustic Stimulation↗