Do induction loops pose a hazard to health?

The RNID actively promotes the use of induction loops as a means of improving communication using hearing aids, particularly in public places. The magnetic flux density, 100-500 nT, needed for effective performance is comparable with fields to which people are exposed every day in the home, and much less than those which can be encountered in the work environment. In the light of current scientific knowledge, the risks to health would appear to be minimal.

An initial investigation into the equivalence of the metal and plastic-cased TDH39 earphones.

Since the adoption of the Telephonics TDH39 pattern of earphone as the main audiometric earphone in use in Britain and elsewhere, there have been a number of superficial changes in its design. The most significant change was around 1980 when the metal-cased design was replaced by a plastic-cased version: the TDH39P. At that time it was assumed that the new earphone was equivalent to the metal-cased version since both types of earphone exhibited similar frequency responses as measured on the IEC 303 acoustic coupler.

Tinnitus. II: Surgical management of conditions associated with tinnitus and somatosounds.

The literature relating to the effects of otological surgery on tinnitus is reviewed. The results of such surgery are often unpredictable with respect to postoperative tinnitus, and ablative surgery may well make the tinnitus worse. The concept of somatosounds (tinnitus arising from outside the auditory pathway) is presented, and the management of some conditions, including patulous Eustachian tube and palatal myoclonus, is discussed.

Tinnitus. III: The practical management of sensorineural tinnitus.

A weekly tinnitus clinic at University College Hospital, London, has been in existence since 1976. By developing a holistic and multidisciplinary approach to the management of tinnitus, we have been able to help the majority of patients referred with severe and disabling tinnitus. We have developed a protocol for the clinical assessment of tinnitus as a disability, and a strategy of investigation and reassurance based on the patient's understanding of the underlying mechanisms involved in tinnitus generation.

Tinnitus. I: Auditory mechanisms: a model for tinnitus and hearing impairment.

A model is proposed for tinnitus and sensorineural hearing loss involving cochlear pathology. As tinnitus is defined as a cortical perception of sound in the absence of an appropriate external stimulus it must result from a generator in the auditory system which undergoes extensive auditory processing before it is perceived. The concept of spatial nonlinearity in the cochlea is presented as a cause of tinnitus generation controlled by the efferents.