PubMed Health⌕ Search

Biomedical subjects

P Portalatini

Publications and source records attributed to P Portalatini.

4 recordsLinked to original sources
PubMed1998

Temporary and permanent threshold shift: an overview.

Temporary threshold shift (TTS) as well as permanent threshold shift (PTS) represent the most common hearing effect of acute and chronic high level acoustic stimulation. TTS is typically related to the traumatizing stimulus spectrum and to the exposure level and duration. The stapedial acoustic reflex as well as the repetition rate of the exposure may influence TTS. PTS is related to a number of factors including exposure duration, subject's age, exposure to other ototoxic factors, presence of impulse noise components, etc. PTS is usually accompanied with alterations of several cochlear functions leading to altered speech discrimination mostly in presence of background noise. The main characteristics of both TTS and PTS are reviewed and discussed.

Acoustic Stimulation↗
PubMed1998

Auditory dysfunction in occupational noise exposed workers.

Occupational noise-induced hearing loss (NIHL) is well known to be an epidemiologically relevant problem. The subjects affected with NIHL show alteration of hearing thresholds as well as a worsening of the cochlear analysis functions and, usually, an impaired speech discrimination in presence of background noise. The study has evaluated the relationships between hearing threshold and equivalent exposure lever per day (Lepd), age and working seniority in a homogeneous sample of occupationally noise exposed workers. Three subgroups were also selected to study the most important cochlear functions as well as nerve and central functions. The first subgroup (Nn) contained normal hearing workers exposed to non-hazardous noise, while the second (Bn) contained workers exposed to high level continuous noise during their work day without clinical evidence of NIHL. The third subgroup (Bd) included subjects affected with the typical 4 kHz notch exposed to the same noise conditions than subgroup Bn. The results show that the hearing impaired subjects have the worst overall cochlear performance; however also the normal hearing workers exposed to hazardous noise have worse performance than subgroup Nn, relatively to high frequency thresholds, frequency resolution, TEOAEs, DPOAEs, stapedial acoustic reflex dynamic parameters. The results suggest that these measures could be used in the monitoring of the NIHL as indicators of subtle alterations of the hearing function.

Acoustic Impedance Tests↗
PubMedDate not supplied

Effects of salicylates on evoked otoacoustic emissions and remote masking in humans.

The aim of this study was to evaluate, in young volunteer subjects, the effects of salicylates on evoked otoacoustic emissions (EOAEs), which presumably reflect an active mechanical process in the cochlea due to outer hair cell (OHC) activity, and on remote masking (RM), which has been proposed as a useful tool in the study of the non-linear cochlear distortion products generated by high-frequency maskers. Data from the present research are consistent with the literature showing a reversible effect of salicylate leading to elevated hearing thresholds and reduced EOAE amplitudes. From the point of view of new findings, the results demonstrate a reversible effect of salicylates on RM magnitude, which decreases as serum salicylate concentration increases. As described previously by other authors, salicylate selectivity inhibits OHC motility and, in consequence, reduces the amplitude of the motion of the basilar membrane. According to these data it is very likely that the observed reduction in RM magnitude after salicylate administration is also the result of the decreased ability of the OHCs to contract and of the reduced basilar membrane motion. The results are consistent with the conclusion that the OHC system function plays a role in producing RM.

Acoustic Impedance Tests↗