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Biomedical subjects

R Chocholle

Publications and source records attributed to R Chocholle.

13 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↗
PubMed1976

[Variations in the loudness of a brief sound compared to another brief sound as a function of the duration of both sounds].

Loudness equalizations between two short 2500 Hz tones (15 to 120 ms, about 50 dB SPL) were made. One tone, either the first or the second one, was twice as long as the other. The intensity level differences between tones of the same loudness were calculated. Results show that the relations between duration and loudness of the tones differ for different subjects. Nevertheless the calculated differences diminished with subject experience. Subject evaluations in accordance with the intensity levels of tones, i.e. independently of the duration, were quite often obtained even for the pairs 15 ms-30 ms.

Acoustic Stimulation↗
PubMed1976

[Relationship between evaluation of the duration and loudness of short sounds].

The relation between loudness and duration judgments of short tones was investigated. Sounds (15 to 120 ms, 2500 Hz, about dB SPL), were exposed in pairs; one tone of the pair, the first or the second one, was twice as long as the other. Subjects had to compare the loudness of the tones, or the duration, or the loudness and the duration at the same time. Results show that the loudness judgments are independent of experiences with duration judgments and of immediate duration judgments, but duration judgments were less precise when loudness judged at the same time.

Auditory Perception↗
PubMed1975

[The auditory intensity discrimination and its audiological and clinical applications (author's transl)].

Studies on this type of discrimination are very interesting, as they can be made at suprathreshold levels. The nature of auditory intensity discriminations and the most useful methods for measuring the auditory intensity difference limens are briefly described. The most important results obtained with normal subjects are then presented; the monaural intensity difference limens, the intensity difference limens measured on one ear while stimulating the other ear by an unvarying tone or a noise, are treated successively. The most important clinical applications of the intensity auditory difference limens are presented (especially, the monaural intensity difference limens, and the difference lemens on one ear in presence of an unvarying tone on the other ear). New explanations of the results obtained in the monaural intensity difference limen tests used are proposed, based on the localization areas in the cochlea, along the auditory nervous system and in the higher auditory centers. New suggestions for the use of the difference limens in audiometry are made.

Acoustic Stimulation↗
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 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↗
PubMedDate not supplied

[Effects of duration on the equal loudness contours of short and brief tones: 40 phones equal loudness contours. Preliminary experiments (author's transl)].

Loudness balances have been obtained between 10-, 20-, 100- and 1,000-ms tones of different frequencies (62.5, 125, 250, 500, 1,000, 2,000, 4,000, 8,000 and 12,000 Hz), and a constant reference tone of 1,000 Hz and 1,000 ms duration at 40 dB SPL. The absolute thresholds were also measured on the same observers at each duration. Progressive shifts of the equal loudness contours appear when the durations become shorter, in the same direction as the corresponding shifts of the threshold curves; the shifts of the equal loudness contours and the corresponding shifts of the threshold curves do not however appear completely similar; some differences may also exist between tones of differing frequencies. These experiments were preliminary ones; some problems arise, in relation with the technique used; improvements appear necessary.

Acoustic Stimulation↗