Spatial Speech-in-Noise Performance in Bimodal and Single-Sided Deaf Cochlear Implant Users.

This study compared spatial speech-in-noise performance in two cochlear implant (CI) patient groups: bimodal listeners, who use a hearing aid contralaterally to support their impaired acoustic hearing, and listeners with contralateral normal hearing, i.e., who were single-sided deaf before implantation. Using a laboratory setting that controls for head movements and that simulates spatial acoustic scenes, speech reception thresholds were measured for frontal speech-in-stationary noise from the front, the left, or the right side. Spatial release from masking (SRM) was then extracted from speech reception thresholds for monaural and binaural listening. SRM was found to be significantly lower in bimodal CI than in CI single-sided deaf listeners. Within each listener group, the SRM extracted from monaural listening did not differ from the SRM extracted from binaural listening. In contrast, a normal-hearing control group showed a significant improvement in SRM when using two ears in comparison to one. Neither CI group showed a binaural summation effect; that is, their performance was not improved by using two devices instead of the best monaural device in each spatial scenario. The results confirm a "listening with the better ear" strategy in the two CI patient groups, where patients benefited from using two ears/devices instead of one by selectively attending to the better one. Which one is the better ear, however, depends on the spatial scenario and on the individual configuration of hearing loss.

Plasticity in tinnitus patients: a role for the efferent auditory system?

HYPOTHESIS: The role of the corticofugal efferent auditory system in the origin or maintenance of tinnitus is currently mostly overlooked. Changes in the balance between excitation and inhibition after an auditory trauma are likely to play a role in the origin of tinnitus. The efferent auditory system can be expected to be involved in such changes. BACKGROUND: The goal of this article was to investigate the current knowledge of the functional efferent auditory system in humans, mostly based on animal research, and to look for new possibilities to try to answer the question of the specific role(s) of the corticofugal efferent auditory system in tinnitus. METHODS: Literature review. RESULTS: Several suggestions for future research are made, for studies in humans as well as in animals. CONCLUSION: We think that it will be worthwhile to investigate the efferent auditory system and its relations to tinnitus in the near future. With this article, we hope to inspire such work.

Wavelet analysis demonstrates no abnormality in contralateral suppression of otoacoustic emissions in tinnitus patients.

The efferent auditory system is thought to play a role in the origin of tinnitus. Part of this system can be tested in humans with contralateral suppression of otoacoustic emissions. Stimulation of the medial olivocochlear efferent system is responsible for this reduction of otoacoustic emissions after contralateral acoustic stimulation. Previous research on patients with tinnitus showed inconclusive results. With wavelet analysis both time and frequency information of the emission can be analysed and compared. Contralateral suppression of otoacoustic emissions was therefore measured in tinnitus patients (n = 26) and normal subjects (n = 37) and analysed using wavelets. No significant difference in suppression was found between the tinnitus patients and the control group.

Contralateral suppression of otoacoustic emissions in tinnitus patients.

OBJECTIVE: To compare the functioning of the medial olivocochlear efferent system between tinnitus patients and control subjects. STUDY DESIGN: Prospective, nonrandomized controlled analysis of suppression of otoacoustic emissions with contralateral acoustic stimulation. SETTING: Tertiary referral center. PATIENTS: Initial analysis of 97 tinnitus patients and 44 control subjects with click-evoked otoacoustic emission measurement. If subjects had reproducible otoacoustic emissions at 80 dB SPL, suppression of otoacoustic emission with contralateral acoustic stimulation was measured with a 65-dB click stimulus. This resulted in inclusion of 44 ears of tinnitus patients and 57 ears of control subjects. INTERVENTION: Suppression of the otoacoustic emissions generated by the 65-dB click stimulus was tested using contralateral broadband noise at 70 dB SPL. Suppression was calculated in half-octave frequency bands centered at 1.0, 1.4, 2.0, 2.8, and 4.0 kHz. MAIN OUTCOME MEASURE: The amount of suppression of the OAE, calculated in half-octave frequency bands. RESULTS: Otoacoustic emission amplitudes were equal in both groups. Contralateral suppression of the signal was found in both patients and controls. The amount of suppression was equal, except for the 2.0- and 2.8-kHz frequency bands in the right ear (p value of 0.03, 0.008, respectively), for which the patients had less suppression. CONCLUSION: The suppression of otoacoustic emissions with CAS seems equally effective in tinnitus patients and healthy controls. The minor differences between both groups suggest subtle differences in the function of the medial olivocochlear efferent system.

Giant Cholesteatoma: Recommendations for Follow-up.

This report presents the management of five patients who presented with giant recurrent or residual cholesteatoma after periods of 2 to 50 years. Their case histories are highly diverse, but all provide evidence of the need for long-term follow-up.

Vascular thoracic outlet syndrome. Longer posterior rib stump causes poor outcome.

OBJECTIVE: To assess the role of the relative length of the posterior rib stump in outcome after transaxillary first rib resection for thoracic outlet syndrome. METHODS: All patients with a transaxillary first rib resection between January 1990 and February 2004 were selected. Relative rib stump length was calculated by dividing the length of the posterior rib stump by the height of the 10th thoracic vertebra. Measurements were made on postoperative X-rays. Outcome was defined as excellent, good, fair, or poor. RESULTS: Surgical outcome was excellent in 11 procedures (28.2%), good in 12 procedures (30.8%), fair in 9 (23.1%), and poor in 7 procedures (17.9%). Correlation of the outcome with the relative rib stump length gives a coefficient of .374 (P=.02). After exclusions of 3 patients with other medical conditions explanatory for remaining pain in the operated limb, the correlation coefficient was .614 (P<.01). CONCLUSION: The relative length of the posterior rib stump is correlated with the outcome after transaxillary first rib resection in patients with thoracic outlet syndrome. First rib resection in patients with proven vascular compression should be as close as possible to the articulation with the transverse process, without injuring the brachial plexus.