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Biomedical subjects

W Szyfter

Publications and source records attributed to W Szyfter.

At least 109 records · Page 6Linked to original sources
PubMed1984

Low frequency thresholds assessed with 40 Hz MLR in adults with impaired hearing.

In a group of 30 adults with impaired hearing, objective thresholds defined with 40 Hz middle latency responses (MLR) were compared with subjective audiometric measures. Frequencies of 0.25, 0.5, and 1 kHz were studied. In order to guarantee a good frequency specificity, subjects presenting large high-frequency hearing loss were particularly chosen. The 40-Hz MLR thresholds were generally worse than the audiometric measures. The average difference was around 12 dB, but in about one-third of the cases it was between 20 and 30 dB. Although not perfect, 40-Hz MLR estimates on low frequencies can be very helpful and deserve further consideration, especially in children.

Adult↗
PubMed1984

40 Hz middle latency responses to low frequency tone pips in normally hearing adults.

Middle latency auditory evoked potentials can be rapidly obtained using a 40/second stimulous rate, taking advantage of response periodicity to accelerate the averaging procedure. This technique was used in 31 normally hearing adults for low frequency response evaluation. Tone pips at 250, 500, and 1000 Hz were employed. The average difference between the middle latency evoked potential threshold and the subjective threshold was 17.9 dB at 250 Hz, 14.5 dB at 500 Hz, and 13 dB at 1000 Hz. The waveform of the response and the latency and amplitude of its main peaks were also analyzed. Thresholds at 500 and 1000 Hz were also determined using brainstem evoked responses in 15 of the subjects. These differed, on average, by 30 dB from subjective thresholds. The 40 Hz MLR paradigm thus appears to be an accurate and rapid method for low frequency threshold evaluation in adults, but it is greatly influenced by the state of arousal. During sleep, response amplitude decreases and threshold increases by about 15 dB. This may be of great concern when interpreting the results in children, in whom low frequency threshold evaluation is of primary importance.

Adolescent↗
PubMed1984

[Occupational damage of the sense of smell].

Workers occupationally exposed to synthetic lacquers vapours and wood dust underwent olfactometric and laryngological examinations. The findings indicated that the synthetic lacquers vapours induced neurotoxic lesions of the smell sense. The wood dust causes only nasal cavity mucous membrane lesions inhibiting smell stimuli access to the smelling area. It was suggested olfactometric tests should be included into the preemployment examinations.

Adolescent↗
PubMed1983

[Usefulness of impedance audiometry in the objective evaluation of occupational hearing loss].

243 workers occupationally exposed to noise have been examined by pure tone audiometry and impedance audiometry. Hearing disturbance have been diagnosed in 145 cases (62%). Impedance audiometry was performed in 74 subjects. In 47 cases (70%) hearing thresholds were found consistent in both methods whereas the other 21 cases (30%) showed different hearing thresholds. Thirteen individuals of that group exhibited hearing impairment in the cochlea. Hearing loss has been simulated in two cases. The Lüscher-Zawisłocki test revealed 1-1.5 dB in all cases. Objective verification of loudness recruitment phenomenon allowed to state cochlear hearing localization in 31 cases.

Acoustic Impedance Tests↗