René Dauman

Assessment and amelioration of hyperacusis in tinnitus patients

Conclusions Tinnitus can be bothersome even without hyperacusis. The good correlation found in this study between the multiple-activity scale for hyperacusis (MASH) score and the overall annoyance of hyperacusis score supports the reliability of self-rating of hyperacusis. Objectives A prospective study was undertaken to investigate the relationships between hyperacusis and tinnitus and to determine whether hyperacusis can be rapidly controlled over time. Material and methods All tinnitus patients seen over a period of 16 months with surnames beginning with the letters A–L (n=249) were assessed during a structured interview using (i) a scale ranging from 0 to 10 for assessing the annoyance of tinnitus and the overall annoyance of hyperacusis and (ii) the newly introduced MASH. Results The annoyance of tinnitus was greater in females. The prevalence of hyperacusis was high (79%). The annoyance of hyperacusis varied. Patients were categorized into five groups according to the hyperacusis annoyance score, as follows: no hyperacusis; mild hyperacusis (≤3); moderate hyperacusis (3.1–5.0); substantial hyperacusis (5.1–7.0); and severe hyperacusis (≥7.1). Individuals with severe hyperacusis were younger than those in the other groups. The correlation between the annoyance of tinnitus and the annoyance of hyperacusis was poor (r=0.35). No audiometric difference was found between categories, whereas self-rated hearing deficiency increased with the annoyance of hyperacusis. A good correlation (r=0.89) was found between the overall annoyance of hyperacusis and the MASH score. Changes over time, assessed in 32 patients investigated at least 3 times, showed more frequent improvement in hyperacusis (63%) than tinnitus (47%).

Summating potential and water balance in Meniere's disease

The summating potentials (SP) to free-field 1-, 2-, 4-, and 8-kHz, 90-dB HL tone bursts were recorded by means of transtympanic electrocochleography in 45 patients divided into three groups: those with Menieres disease, those whose diagnosis was uncertain, and control subjects. The similarities across frequencies between the human SP (promontory) and the experimental SP (DIF component from basal turn) suggest that the SP recorded in electrocochleography originates mostly from the base of the cochlea; negative values were observed at low frequencies (1 to 2 kHz), positive values at high frequencies (8 kHz). Patients with Menieres disease showed significantly larger SP values than control subjects. The effect of orally administered glycerol on the SP and action potential amplitudes was evaluated by means of automated recordings repeated every 5 minutes. Summating potential values were remarkably constant in the control group. A decrease in SP absolute amplitude was observed in most patients with Menieres disease and some subjects with uncertain diagnoses, specifically at low frequencies. These changes were frequently associated with action potential amplitude and auditory threshold improvements at low frequencies. It is assumed that the glycerol-induced SP changes at low frequencies are related to modifications in the low frequency mechanical response of the basilar membrane at the basal turn.

Recent Advances in Tinnitus.

Tinnitus can be the most debilitating symptom faced by people with hearing impairments. In the past 10 years, there has been a large increase in tinnitus research and in the development of clinical protocols. New animal models and physiological procedures provide an important contribution to the understanding and measurement of tinnitus. The annoyance of tinnitus likely depends on its loudness and the psychological makeup of the patient. The loudness of a persons tinnitus can be compared with the equivalent loudness of a 1000 Hz tone in a normal ear. Several questionnaires have recently been introduced to quantify the handicap caused by tinnitus. Tinnitus maskers are apparently ineffective for most patients but they can be helpful in a few patients. Medications are largely ineffective in reducing tinnitus in most people. However, several psychological techniques for reducing the stress associated with tinnitus are currently under investigation, and preliminary results show some promise. Tinnitus can be reduced by electrical stimulation in a few patients, and this is also an important area for future research.

Further Validation of the Iowa Tinnitus Handicap Questionnaire

The ease of use of the French version of the Tinnitus Handicap Questionnaire was assessed in a group of 100 unselected individuals with tinnitus, 57 of whom agreed to take part in the survey. In addition to the instructions commonly used with this inventory, participants were invited to make any comments they wished about each item and to give their opinion of the content and presentation of the questionnaire. Nineteen subjects (33.3%) experienced difficulties with assigning a score to at least one item and one particular item was largely responsible for this problem. Increased systematic use of quantitative and qualitative data with this type of questionnaire is advocated.

Electrocochleographic Measures of Cochlear Frequency Selectivity in Hearing Loss of Cochlear Origin

One of the basic functions of the cochlea is to separate out the frequency components which are present in complex sounds. This frequency selectivity can be measured objectively in the clinic from the compound action potential (AP) during transtympanic electrocochleography, using a two-tone masking paradigm. An AP is evoked by a test tone near to threshold, and a measure is made of the frequency bandwidth over which this AP can be suppressed by a continuous pure tone masker. In normal-hearing subjects, this frequency range is 0.17-0.39 octaves (test tone pip at 4 or 8 kHz). In patients with cochlear deafness, this bandwidth is greatly enlarged, ranging from 0.42-2.2 octaves. Some observations suggest that a deterioration in frequency selectivity can occur before any important threshold elevation. The early detection of this could be a warning sign of potential cochlear susceptibility. In the clinic the measure is already of use: a deterioration is a positive indication of cochlear involvement in a hearing loss.

Long-term Outcome of Childhood Hearing Deficiency

This report is based on the questionnaire responses of 95 young hearing-impaired adults (39 with moderate, 20 with severe and 36 with profound hearing loss) who were investigated in the department of paediatric audiology during childhood. Half of the individuals were educated in ordinary school (integration) and half in an institution for hearing-impaired children. Responses on social and professional insertion were compared with audiometric threshold and educational setting. Results indicate that both hearing level and educational environment influence current mode of communication and use of hearing aids. Familial factors also seem to have an influence. Oral communication is a poor predictor of employment, whereas professional qualifications enhance the chances of finding a job. Obtaining a non-professional degree appears to be unsuited for improving the employment rate of the hearing-impaired child.This report is based on the questionnaire responses of 95 young hearing-impaired adults (39 with moderate, 20 with severe and 36 with profound hearing loss) who were investigated in the department of paediatric audiology during childhood. Half of the individuals were educated in ordinary school (integration) and half in an institution for hearing-impaired children. Responses on social and professional insertion were compared with audiometric threshold and educational setting. Results indicate that both hearing level and educational environment influence current mode of communication and use of hearing aids. Familial factors also seem to have an influence. Oral communication is a poor predictor of employment, whereas professional qualifications enhance the chances of finding a job. Obtaining a non-professional degree appears to be unsuited for improving the employment rate of the hearing-impaired child.

Development of Capacities of Communication and Socialization in Young Deaf Children: Utility of a Common Assessment Protocol for Implanted or Hearing Aid Equipped Children

Pediatric cochlear implantation has attracted a growing interest among health professionals, but it has also encountered opposition on the deaf community. It is therefore incumbent upon the medical teams that carry out this procedure to furnish scientific arguments demonstrating the benefits of this technique for the age group 2 to 4 years and its innocuousness for the childs later psychological development. With this in mind, we have elaborated an assessment protocol adapted to very young deaf children, regardless of whether they have implants or hearing aids. The present report describes two tests of the protocol, chosen because they meet needs which until now have been insufficiently, or not, met. The first of these tests aims at assessing, as early as the age of two, oral and gestual production thanks to sequential images. The second test is the most original element of our psychological protocol: analysis of the childs interactional attitudes through filmed game situations. The initial results from a group of children recently implanted and from another group equipped with hearing aids are presented. These children continue to be seen at regular intervals. It is reasonable to hope that this kind of study will afford objective arguments to the debate in progress.

Audiometric and Electrophysiological Correlations in Sudden Deafness

Electrophysiological measures were collected over 3 years in 61 cases of sudden deafness. Electrocochleography (ECochG) and Auditory Brainstem Responses (ABR) using click stimuli were recorded down to threshold and compared with pure-tone and speech audiometry data. This study was intended to precise 1) localization of the disorder, 2) prognosis, 3) analysis of the contribution of different frequencies in click-evoked responses. The following results are: 1) In most cases the observations indicated that the inner ear was affected. 2) However, in 19 cases electrophysiological measures revealed a retrocochlear involvement. Four acoustic neuromas were evidenced by CT scan. In 3 of these, audiometric and electrophysiological thresholds returned merely to normal levels after medical treatment, while brainstem responses remained delayed. Thus in these cases recovery would seem to be related to release of vascular compression in the auditory internal meatus. 3) When the latencies of the VII nerve potential (N1) and wave V (PV) were short, and the therapy undertaken early, a good recovery was often obtained. 4) When recovery occurred on low frequencies only, the electrophysiological responses to the click showed slight latency increases.

Comparison between Bilateral Cochlear Implants and Neurelec Digisonict SP Binaural Cochlear Implant: Speech Perception, Sound Localization and Patient Self-Assessment

An alternative to bilateral cochlear implantation is offered by the Neurelec Digisonict SP Binaural cochlear implant, which allows stimulation of both cochleae within a single device. The purpose of this prospective study was to compare a group of Neurelec Digisonict SP Binaural implant users (denoted BINAURAL group, n = 7) with a group of bilateral adult cochlear implant users (denoted BILATERAL group, n = 6) in terms of speech perception, sound localization, and self-assessment of health status and hearing disability. Speech perception was assessed using word recognition at 60 dB SPL in quiet and in a ‘cocktail party’ noise delivered through five loudspeakers in the hemi-sound field facing the patient (signal-to-noise ratio = +10 dB). The sound localization task was to determine the source of a sound stimulus among five speakers positioned between –90° and +90° from midline. Change in health status was assessed using the Glasgow Benefit Inventory and hearing disability was evaluated with the Abbreviated Profile of Hearing Aid Benefit. Speech perception was not statistically different between the two groups, even though there was a trend in favor of the BINAURAL group (mean percent word recognition in the BINAURAL and BILATERAL groups: 70 vs. 56.7% in quiet, 55.7 vs. 43.3% in noise). There was also no significant difference with regard to performance in sound localization and self-assessment of health status and hearing disability. On the basis of the BINAURAL group’s performance in hearing tasks involving the detection of interaural differences, implantation with the Neurelec Digisonict SP Binaural implant may be considered to restore effective binaural hearing. Based on these first comparative results, this device seems to provide benefits similar to those of traditional bilateral cochlear implantation, with a new approach to stimulate both auditory nerves.

Short-term Effectiveness of Medial Efferents does not Predict Susceptibility to Temporary Threshold Shift in the Guinea Pig

The 2f1-f2 distorsion product (DPOAE) was measured in conjunction with contralateral noise to evaluate the short-term effectiveness of the olivocochlear efferents in guinea pigs (GPs). An attenuation effect was observed predominantly between 1 and 6 kHz when primary tones were set at 65 dB SPL (contralateral noise of 55 dB SPL). Subsequently, GPs were exposed to a 2 kHz tone of 87 dB SPL for 40 min, using DPOAEs as an estimate of cochlear sensitivity. The response of the cochlea appeared variable. In order to investigate whether effectiveness of efferents plays a role in temporary threshold shift (TTS), the responses of the cochlea to overstimulation were classified into three groups: i) clear cochlear change with complete recovery or actual TTS (group A1); ii) clear cochlear change with incomplete recovery (group A2); iii) mild or no change in cochlear function (group B). No relationship was found between the attenuation effect measured before noise overexposure and the susceptibility to TTS. Animals with a significant attenuation effect could fit into any of the three groups. In addition, the recovery from loud sound exposure was not paralleled with the changes occurring over time in the attenuation effect. Therefore, the conclusion that short-term effectiveness of medial efferents does not predict susceptibility to TTS in the GP is suggested.