. "Case Study 51: Acoustic Trauma Caused by the Telephone: A Report of Two Cases." Environmental Medicine: Integrating a Missing Element into Medical Education. Washington, DC: The National Academies Press, 1995.
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Environmental Medicine: Integrating a Missing Element into Medical Education
Fig. 1. Audiometrical results of the first patient suffering from an acoustic trauma due to a loud sound transmitted by a cord-type telephone. a Puretone audiogram. b Thresholds and decay of the stapedial reflex. c ABR (right ear on the left, left ear on the right). The audiogram shows a low and midfrequency sensorineural hearing loss of the left ear. The thresholds of the stapedial reflex are normal as well as the interwave intervals and amplitude ratios of the ABR.
phones are officially prohibited. Standards for maximum peak acoustic power (120 dB) are based on advice edicted by the International Telegraph and Telephone Consultative Committee (ITTCC). This present regulation is strict and thereby the ‘Caisse Nationale suisse d’Assurance en cas d’accident’ (National Insurance Company for Accidents, CNA) has not been notified of any case of hearing loss resulting from the use of telephones during the last two decades. However, in the past few years, unofficial telephones have become available on the market, thus escaping control by the PTT.
We report two cases of hearing loss in individuals using these unofficial devices. In 1 patient the auditory insult resulted from the transmission of a loud, extraneous crack sound by a cord-type telephone: this is the first case report of trauma caused by a non-cordless telephone.
A healthy 56-year-old woman was referred to the ENT Department of the University Hospital of Geneva on October 28, 1986. She had been treated for 3