Enriched acoustic environment rescales auditory sensitivity.

Loudness perception may be controlled by a central gain, possibly dependent on the mean level of the acoustic environment. Owing to hearing loss, for instance, a decrease in sensory inputs could increase this central gain and cause an auditory hypersensitivity or hyperacusis. According to this model, individuals with hyperacusis, provided with an enriched acoustic environment specifically designed to compensate for the decrease in sensory inputs, should show an improvement in their hyperacusis.

Reduced attention shift in response to auditory changes in subjects with tinnitus.

A current idea about the persistence of tinnitus is that fixation of this phantom auditory perception in the central auditory system may be influenced by attention to it. The present study investigated the mechanisms of involuntary attention and analysed performance in categorising sounds in tinnitus, simulated-tinnitus and control subjects. The sounds were presented in one ear and were preceded by presentation of frequent and deviant stimuli in the other ear.

Investigation of functional hemispheric asymmetry of language in tinnitus sufferers.

The authors tested functional hemispheric asymmetry through word dichotic listening and lateralized lexical decision tasks in tinnitus patients and controls stimulated by a continuous tinnitus-like noise to test the influence of a tinnitus-like external stimulation. A classic right-ear advantage was shown in the auditory task for all but right-ear tinnitus patients, who performed as equally badly when the stimuli were presented to the right and left ears. Concerning the visual task, all participants demonstrated the expected right visual field advantage for word stimuli.

Psychoacoustic characterization of the tinnitus spectrum: implications for the underlying mechanisms of tinnitus.

In this study, an original psychometric procedure was used in order to characterize in more detail than in previous studies the different perceptual components of tinnitus, i.e. auditory sensations which are perceived in the absence of a corresponding external acoustic stimulus.

Perceptual correlates of neural plasticity related to spontaneous otoacoustic emissions?

The inner ear contains receptor cells that oscillate spontaneously, generating waves that propagate backward in the cochlea, ultimately causing sound to be radiated into the ear canal--the spontaneous otoacoustic emissions (SOAEs). Except in rare conditions, these internally generated signals appear to go unheard. The intensity of SOAEs admittedly hovers near the threshold of detection, but they are essentially continuous and perhaps last a lifetime.

Loudness changes associated with the perception of an auditory after-image.

The Zwicker tone (ZT) is an auditory sensation that occurs following the presentation of broadband noise containing a spectral notch. The present study aimed to test whether the changes in auditory thresholds that have been shown to follow the presentation of the ZT inducer are accompanied by suprathreshold effects. Using an interaural loudness-balance procedure, the loudness of probe tones presented after notched and after flat noise was compared.

An auditory negative after-image as a human model of tinnitus.

The Zwicker tone (ZT) is an auditory after-image, i.e. a tonal sensation that occurs following the presentation of notched noise.

Validation assessment of a French version of the tinnitus reaction questionnaire: a comparison between data from English and French versions.

The present study compares the results obtained on original and French versions of the TRQ (Tinnitus Reaction Questionnaire) initially published by Wilson, Henry, Bowen, and Haralambous (1991) in English to evaluate the psychological distress of tinnitus sufferers. Reliability and validity of the French translation were determined using data from 173 normal hearing or hearing-impaired patients with tinnitus lasting from 1 month to 41 years. They completed the translated questionnaire and a short version of the Minnesota Multiphasic Personality Inventory.

Towards an objectification by classification of tinnitus.

Objective: The objectives of this study are to identify the presence of tinnitus and classify its different forms, in terms of changes in noise.

Methods: Late auditory evoked responses (LAERs) were recorded from Fz in response to 1000 Hz tone bursts of various intensities, in 13 tinnitus-free subjects and in 25 tinnitus sufferers (16 bilateral and 9 unilateral tinnitus sufferers). A classification of different forms of tinnitus, in terms of changes in noise, was also undertaken.

A selective imaging of tinnitus.

We selectively imaged the neural correlates of tinnitus, by contrasting a condition with no phantom auditory sensation with a condition during which tinnitus is present, using a rare form of tinnitus elicited by eye movements. Using positron emission tomography (PET), we demonstrate that phantom auditory sensation increases regional cerebral blood flow bilaterally in temporo-parietal association auditory areas but not in the primary auditory cortex. These results confirm that conscious perception does not necessarily require activation in primary areas and suggest that the perceptual qualities of tinnitus, e.

Psychopathological profile of tinnitus sufferers: evidence concerning the relationship between tinnitus features and impact on life.

This study involving 281 French tinnitus sufferers sought to investigate possible correlations between psychopathological profile and scores obtained from three tinnitus questionnaires. The patients all completed a French version of the Mini-Mult--a shortened Minnesota Multiphasic Personality Inventory--and French translations of three questionnaires designed especially for the clinical assessment of tinnitus: Tinnitus Reaction Questionnaire (TRQ), Subjective Tinnitus Severity Scale (STSS) and Tinnitus Handicap Questionnaire (THQ). Significant correlations were found (p < 0.

[Validation of French translation of the "Tinnitus Reaction Questionnaire", Wilson et al. 1991].

The present study proposes a validation of a french translation of the TRQ initially published by Wilson et al., for evaluating the psychological distress of tinnitus sufferers. The 26 items translated into french were used on a sample of 173 tinnitus sufferers, who also filled out the Mini-Mult, a short version of the MMPI proposed by Kincannon.

Influence of contralateral noise on distortion product latency in humans: is the medial olivocochlear efferent system involved?

To test the hypothesis of temporal modifications of cochlear responses when medial efferents are activated, otoacoustic emission latencies were estimated in 16 normal human subjects, in the presence and absence of a contralateral broadband noise, using measurements of the phase of the 2f1-f2 distortion product (group latency method). Significant decrease in the latency of lower frequency (0.8-2.

Suppression of otoacoustic emission is unchanged after several minutes of contralateral acoustic stimulation.

The influence of variable durations of contralateral acoustic stimulation on the suppression of click-evoked otoacoustic emissions was investigated in order to determine whether olivocochlear efferent fibers are equally effective whatever the acoustical stimulation duration or if they show fatigue. The suppression effect was measured for contralateral stimulus durations ranging from 10 to 180 s prior to the onset of otoacoustic emission recording, and continuing throughout the recording time (60 s). No significant stimulus duration effect was found.

[Translation and validation of the questionnaire "Tinnitus Handicap Questionnaire, 1990].

Objective: The Tinnitus Handicap Questionnaire (THQ) measures subjective tinnitus handicap in terms of emotional, social, and health impact (factor 1), hearing (factor 2), and perception of tinnitus (factor 3). A French version of the THQ was used with 178 tinnitus sufferers in ENT consultation. Internal validity was confirmed by correlations between (i) semigroups of items (Cronbach's alpha), (ii) item and total scores, and (iii) individual items, for each factor (Pearson's r), and was found to be strong (alpha = .

Auditory efferents involved in speech-in-noise intelligibility.

Following studies proposing that medial olivocochlear efferents might be involved in the processing of complex signals in noise, we tested the involvement of efferent feedback in speech-in-noise intelligibility. Two approaches were used: measures of speech-in-noise intelligibility in vestibular neurotomized patients with cut efferents and comparison with normal hearing subjects; and correlations between effectiveness of olivocochlear feedback, assessed by contralateral suppression of otoacoustic emissions and speech-in-noise intelligibility in normal subjects. Contralateral noise improved speech-in-noise intelligibility in normal ears.

2f1-f2 distortion product otoacoustic emission latency: changes with frequency and level of primaries.

Distortion product otoacoustic emissions (DPOAEs) provide a non-invasive and relatively direct method for evaluating cochlear travel time in humans. In the present study, the 2f1-f2 DPOAE latency was deduced from DPOAE phase shift according to f2 frequency shift, with f1 being fixed, using the ILO92 system. Latencies of 2f1-f2 DPOAEs were recorded at various primary frequencies and levels.

Phase delay measurements of distortion product otoacoustic emissions at 2f1-f2 and 2f2-f1 in human ears.

The present study used distortion product otoacoustic emission (DPOAE) latency as a tool to provide information about the generation sites of 2f1-f2 and 2f2-f1 DPOAEs in humans. The DPOAE 2f1-f2 is supposed to be generated near the f2 site, but little is known about the 2f2-f1 DPOAE processing in humans. The present work sought to test several hypotheses as to the possible generation of 2f1-f2 at the f2 site and of 2f2-f1 at the 2f2-f1 site as well as their backward reflection site, by comparing latencies of the two DPOAEs, under appropriate frequency manipulation.

Antinociceptive effects of oral clonidine and S12813-4 in acute colon inflammation in rats.

Acute colonic inflammation was induced by perendoscopic injection of 50 microleters of dilute formalin (5%) in the depth of the colonic wall (c.w.) in rats.

Contralateral acoustic stimulation induces a phase advance in evoked otoacoustic emissions in humans.

In 28 normal-hearing human subjects, the medial olivocochlear efferent system was activated by contralateral acoustic stimulation which is able to mimic the inhibitory effects of electrical stimulation of the crossed olivocochlear bundle. A first experiment on 16 subjects demonstrated that a contralateral white noise of 35 dB SL was able to induce temporal changes on transiently evoked otoacoustic emissions in response to clicks of 63 dB SPL. These temporal changes consisted of an advance of click-evoked otoacoustic signals in 87% of cases and is referred to as phase-shift effect.

Is perilymphatic pressure altered in tinnitus?

Tinnitus is characterized by the continuous or intermittent auditory perception of various sounds (buzzing, whistling, etc.) in the absence of any external stimulus. Perilymphatic hyperpressure is one of the numerous mechanisms which could hypothetically be involved in tinnitus generation.

Evidence of a medial olivocochlear involvement in contralateral suppression of otoacoustic emissions in humans.

Otoacoustic emissions (OAEs) evoked by click stimuli were recorded in both ears of 20 normal human subjects, in the presence and absence of a contralateral masking broad band noise. No difference in the amplitude of OAE suppression was noted between the first tested ear and the second one. In addition, 20 pathological subjects were tested according to the same protocol.

Contralateral suppression of transiently evoked otoacoustic emissions and tinnitus.

The present paper reports individual data obtained in three different patients who consulted for unilateral tinnitus in the Department of Otolaryngology. After pure tone and high-frequency audiometry, Audioscan audiometry was recorded, and tinnitus measurement which comprised a determination of pitch and loudness matches. Spontaneous, transient evoked and 2f1-f2 distortion product otoacoustic emissions at 65 dB SPL stimulus intensity were then determined.

Contralateral auditory stimulation and otoacoustic emissions: a review of basic data in humans.

The influence of contralateral auditory stimulation on otoacoustic emissions (OAE), spontaneous OAE, evoked OAE and acoustic distortion products, can be summarized as follows: (1) alteration (mainly a decrease) of OAE amplitude; (2) alteration of response spectrum (upward shift frequency of SOAE); (3) alteration of phase; (4) effect dependent on intensity of contralateral stimulation; (5) effect inversely dependent on intensity of ipsilateral stimulation; (6) frequency specificity of the suppressive effect. Involvement of the medial olivocochlear bundle is highly probable but one cannot exclude a double pathway including also the acoustic reflex.

Inflammation of the colonic wall induced by formalin as a model of acute visceral pain.

Acute inflammation of the sigmoid wall was induced by perendoscopic injection of formalin (50 microliters, 5%) under brief anesthesia in rats. The procedure was followed by behavioral patterns that significantly differed from those in animals injected with isotonic saline instead of formalin. Analysis of the formalin-induced behaviors allowed for the calculation of a pain score that evolved in a biphasic manner along the 3 h of test.