Investigating the effect of eye movement desensitization and reprocessing on internalized stigma in patients with major depressive disorder: a randomized controlled trial.

The most basic function of the auditory system is to determine whether a sound is present time a subject is exposed to a sound stimulus. Many behavioral tests address the ability of the auditory system to perform this task. For stimulus interval, the auditory system classifies a stimulus as being present or absent. The absolute threshold of hearing is defined for a subject as the sound pressure level at which a certain fraction of stimulus presentations are correctly classified by the subject. Behavioral thresholds are fundamentally different from thresholds based on the electrical response of the brainstem to sounds, known as the auditory brainstem response (ABR). Averaging hundreds of ABR trials to repeated presentations of the same sound stimulus reveals a stereotypical temporal pattern. The ABR threshold is defined as the sound pressure level at which the ABR evidences the presence of a stimulus. An extensive array of methods have been developed to objectively determine ABR threshold ( and references therein). Although the ABR threshold is a useful diagnostic, it does not access how well the auditory system responds to sound presentation. Suprathreshold hearing can also be assessed using the average ABR. The amplitudes and latencies of characteristic peaks in the average ABR, known as Jewett waves, respectively rise and fall with increasing stimulus levels. Waves are, however, difficult to identify in all subjects and at low levels. Although the disappearance of a wave may indicate hearing impairment, how to associate changes in wave amplitudes or latencies with suprathreshold hearing loss remains an open question.