The aim of the present study was to study patterns in the extended spectrum of the human hearing (0.125 to 20 kHz) in order to obtain reference thresholds. Then, we compare our values with existing results at extended high-frequencies (8 to 20 kHz) in an attempt to establish new standards for potential international adoption. A prospective study in a group of otologically healthy subjects. A total of 645 subjects aged between 5 and 90 years were recruited. Pure-tone thresholds were determined for conventional and extended high-frequencies. There was an increase in the hearing thresholds as a function of frequency and age. For the 20 to 69 years old group, thresholds were lower in females than in males, especially at 12.5 and 16 kHz. Our threshold values are comparable to those presented in previous studies that used different instrumentation and populations. When comparing different studies the hearing thresholds were found to be similar. Therefore, it would be possible to establish international standard thresholds.

Sudden deafness constitutes a diagnostic challenge. Classically, 2 causes, viral and vascular, are considered in the origin of idiopathic sudden hearing loss. More recently added to the list of possibilities are rupture of the membranous labyrinth and immune-mediated sensorineural hearing loss. The latter can be either primary and localized to the inner ear or, in perhaps fewer than one third of cases, secondary to generalized systemic autoimmune disease. The purpose of the present review is to define immune-mediated sudden sensorineural hearing loss as a distinctive entity, on the basis of clinical, immunologic, and pathological findings, and suggest a profile of the typical patient.

Background and purpose: Ototoxicity is a known adverse effect of cisplatin (CDDP). Since apoptosis is involved in the development of some pathological conditions associated with the administration of anticancer drugs, we examined, using immunohistochemical and electrophysiological techniques, the apoptotic changes in the cochlea of Sprague‐Dawley (SD) rats after an injection of CDDP (5 mgkg^‐1 body weight).Experimental approach: Luciferase assays were used to determine the different caspase activities and ATP levels in protein extracts of whole cochleae. The expression of several apoptotic‐related proteins was measured by means of Western blotting. These analyses were performed 2, 7 and 30 days after the CDDP injection. The auditory brain stem response was obtained before and at the different times after the injection of CDDP, before the animals were killed.Key results: CDDP significantly increased the levels of caspase‐3/7 activity and active caspase‐3 protein expression and caspase‐3 immunofluorescence staining, caspase‐9 activity, and Bax protein expression but decreased Bcl‐2 protein expression within the rat cochleae. Threshold shifts were significantly elevated 2 days after CDDP treatment.Conclusions and implications: These findings support the hypothesis that cisplatin‐related apoptosis evokes an intrinsic pathway of pro‐apoptotic signalling within the rat cochleae. Thus, selective inhibition of the sequence of events involved in the intrinsic apoptotic pathway could provide a strategy to minimize cisplatin‐induced ototoxicity.British Journal of Pharmacology (2007) 152, 1012–1020; doi:10.1038/sj.bjp.0707405; published online 1 October 2007