PubMed Health⌕ Search

Biomedical subjects

M C Botte

Publications and source records attributed to M C Botte.

8 recordsLinked to original sources
PubMed1979

Temporary threshold shift, loudness, and auditory evoked potentials.

TTS2 of 20dB was produced in a group of subjects using a 1000 Hz pure tone. All TTS and related measurements were made at 1500 Hz. The recovery of TTS, and of TLS or 'temporary loudness shift' (measured against a reference tone at 20db, 40dB and 60dB SL in the opposite ear), as well as N1-P2 amplitude of the Vertex potential, were plotted. There was an orderly recovery of both TLS and TTS although the rate of recovery of the latter was noticeably more rapid. Recovery of N1-P2 amplitude was much less orderly, although it did recover in much the same way. When the amplitudes were measured at 40dB SL the recovery was more orderly and followed the course of TTS more closely. It was concluded that any relation between N1-P2 amplitude and growth of loudness was indirect.

Acoustic Stimulation↗
PubMed1979

[Auditory fatigue in individuals having sustained an acoustic trauma (author's transl)].

A comparison was made between losses of auditory sensitivity after a fatiguing sound exposure of the ear in two groups of subjects: audiometrically normal subjects and subjects with early acoustic trauma. Subjects with cochlear impairment sustained an auditory loss apparently less than that of normal subjects when this loss is measured at threshold level. However, at supraliminal levels the loss of sensitivity, as measured here, would seem to be equal in both groups of subjects. In fact, the dynamics of sonic variations, already reduced by the cochlear impairment, is even further decreased by the effects of fatigue.

Audiometry↗
PubMed1975

[Audiological observations of a patient with auditory agnosia].

A case is reported in which a patient was become unable to identify all kinds of auditory material, including speech, despite only subnormal audiometric thresholds (i.e. "auditory agnosia"). The following audiological disorders were shown: some fragility in the perception of brief sound stimuli, difficulties to apprehending prolonged series of stimuli (rhythms), defective sound localization, an increase in the homolateral and in the contralateral effects of masking sounds. On the other hand, differential thresholds for frequency and for intensity, as well as fusion thresholds, were little affected, or unaffected. A complete dissociation appeared between the auditory evoked potentials and the audiometric thresholds; a year after the first examination, and the following years, the auditory potentials were largely reduced, or even have elapsed for one ear, while the audiometric thresholds seem to remain nearly the same.

Agnosia↗
PubMedDate not supplied

[Auditory-evoked responses to a monaural or a binaural click, recorded from the vertex, as in two temporal derivations; effect of interaural time differences (author's transl)].

The auditory-evoked responses have been recorded on 5 subject by vertex, right temporal and left temporal electrodes simultaneously. 30 dB sensation level clicks were used as stimuli; one click was presented only to the right ear, or one click only to the left ear, or one click to the right ear and another click to the left ear with a variable interaural time difference in this latter case (0-150 ms). The N-P amplitude variations and the N and P latency variations have been studied and compared to those observed in the perceived lateralizations of the sound source.

Acoustic Stimulation↗
PubMedDate not supplied

[Auditory fatigue in man. Comparison of recovery at threshold and above threshold].

Using a 1 000-Hz pure tone, a TTS2 of 20 dB was produced in a group of subjects. Recovery from this TTS was studied at 1 500 Hz and the measurements were extended to 320 min to encompass the course of recovery, The recovery of the temporary impairment of threshold was plotted concurrently with that of the temporary masked threshold shift (TMTS) of the 1 500 Hz tone in the presence of a 700 Hz masking tone. This technique provided an indirect measurement of loudness loss at 10. 20, 30, 40, 50 and 60 dB SL. The time required for complete recovery depended upon whether one measured TTS or TMTS; the longest recovery times were, in respect of the masked threshold, at low sensation levels.

Acoustic Stimulation↗