Sweep-induced acceleration in loudness change and the "bias for rising intensities".

A pure tone changing continuously in intensity shows sweep-induced fading (SIF) of loudness as intensity sweeps down and may show a lesser degree of sweep-induced enhancement (SIE) as intensity sweeps up (Canévet & Scharf, 1990); the former effect has been called decruitment, the latter upcruitment. An opposite effect-upsweeps being judged to show more loudness change than downsweeps--has been reported by Neuhoff (1998). These disparate results might stem from several procedural differences.

Relationship between auditory perception skills and mismatch negativity recorded in free field in cochlear-implant users.

This study investigated the ability of cochlear-implanted patients to discriminate tone bursts in free field using the electrophysiological recordings of mismatch negativity (MMN). Seven cochlear-implanted patients (CIP) and eight control subjects (CS) were tested. Event-related potentials were recorded from either 32 or 64 electrodes in response to binaural stimuli using a passive oddball paradigm.

Voice onset time encoding in patients with left and right cochlear implants.

Stop-consonant discrimination was investigated in normal-hearing listeners and cochlear-implanted patients (CIP) by recording auditory evoked potentials (AEPs) to /b epsilon/ and /p epsilon/ syllables. This study demonstrates that: (i) AEPs show time-locked components that mimic the temporal structure of the stimuli, indicating that both patients and control subjects encode those syllables according to the temporal cue (voice onset time) characterizing the voiced/voiceless contrast; (ii) the side of implantation does not affect the general structure of AEPs and /b epsilon/-/p epsilon/ discrimination thresholds (measured separately with a psychophysical procedure); (iii) poor time-locking to the syllables' temporal structure is associated with poor discrimination. This suggests that EEG investigation of temporal-processing provides an objective index of speech perception in CIP and could be used in implanted children.