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Biomedical subjects

P Grateau

Publications and source records attributed to P Grateau.

At least 19 recordsLinked to original sources
PubMed1998

Intrinsic differences in hearing performances between ears revealed by the asymmetrical shooting posture in the army.

Left ear noise-induced hearing losses are dominant in the army. The common explanation is the asymmetrical effect of the shooting posture. However, firm evidence to support this possibility is still lacking. In the French army shooters, eye preference rather than hand preference for shooting determines the side of shooting and hence the ear more exposed to noise. To test whether left-right asymmetry of hearing thresholds really relates to the shooting posture, we analyzed audiograms from 644 officers of the infantry and artillery branches. The interaural differences reached 7 dB for right-eyed subjects, and less, about 5 dB, for left-eyed subjects at 6-7 kHz, both with disadvantage for the left ear. In contrast, hearing thresholds of both groups in the low frequency range were significantly better for left ears. Our results suggest each ear has different intrinsic characteristics. The right cochlea might be a less sensitive but more robust sensor than the left cochlea, which might be a finer sensor but more sensitive to noise.

Adult↗
PubMed1993

[Computer analysis of audiograms in epidemiologic surveillance of cohorts exposed to excessive noise].

We have developed a method for the assessment of auditive loss using a sample of 1794 Bekesy audiograms recorded in young military students. A rectangular digital filter was used to smooth rough audiogram signals so as to detect pathological patterns such as scotoms and recruitments. Three factors were extracted from principal component analysis. They were correlated with the usual auditory indices and explained 70% of the total observed variance. The first factor is a general indicator of deafness, while the second and third describe the shapes of the hearing threshold level (asymmetry and convexity). This method can be used for rapid identification of suspect audiograms and is thus of value for epidemiological surveillance of populations exposed to impulsive noise.

Adolescent↗
PubMed1992

Effectiveness of earplugs in high-intensity impulse noise.

The efficiency of different types of earplugs was assessed by means of Békésy audiometry following the exposure of 42 human subjects to weapon impulses. The peak pressure of the impulses ranged from 2.3-27.8 kPa (from 161 to 183-dB peak SPL) and the A-weighted equivalent level (over 8 h) of each exposure ranged from 100-114 dB. All subjects wore earplugs fitted by an experienced individual. The devices tested included one brand of conventional foam earplugs and a number of different models of perforated earplugs, one type of which had been previously shown to provide nonlinear attenuation. Perforated earplugs were tested because they provide better speech communication than conventional passive earplugs, and in the nonlinear case also afford attenuation that increases with the peak pressure of the impulses. The temporary threshold shifts (TTSs) observed in these experiments were very small and indicated no significant hazard for hearing. Well-fitted perforated earplugs seem to be able to protect the ear from infrequent exposures to the high-level impulses produced by small and large weapons while allowing good speech communication, and without impairing the operational capacity of soldiers who must remain aware of their acoustic environment.

Adult↗
PubMed1991

Delayed temporary threshold shift induced by impulse noises (weapon noises) in men.

Most of the available information on the effects of impulse noise on hearing is derived from temporary threshold shift (TTS2) measurements performed 2 min after a single exposure to small-weapon noises. TTS is known to recover as a linear function of the logarithm of time when it is induced by a continuous noise of moderate intensity. Following the exposure to impulse noise, several investigators have reported individual exceptions to the log-time relation, e.g. increases in TTS during the first hour of recovery. These authors observed a 'rebound recovery function' for most of the exposed men, and they conclude that this phenomenon '... has implications for the use of TTS in the construction of damage risk criteria for hazardous noise exposure ..., a single measure, such as the widely used TTS2 may not be an adequate index of the magnitude of the TTS'. In order to thoroughly investigate in man the existence of 'delayed' TTS following the exposure to actual weapon noises, the 'French Committee on Weapon Noises' carried out the following study. Three groups of soldiers (28 subjects) wearing no hearing protection were exposed in the free field over 2 days to impulse noises produced by a rifle. Békésy audiograms were obtained from each subject just before the exposure, and at 5 min, 1 h and 4 h after exposure. All audiometric tests were carried out even when no TTS was observable in the first postexposure audiogram. A significant number of subjects showed a 'delayed TTS' and/or 'rebound recovery'. The maximum TTS was observed at 1 h after exposure, but the observation of a delayed recovery and a rebound recovery indicate that audiometric tests should be performed in all cases at least up to 4 h after the exposure. More detailed work is necessary to establish what changes may be necessary in the present damage risk criteria for impulse noises of a very high level.

Adult↗
PubMed1987

[Laryngeal lesions caused by explosions (laryngeal blasts)].

Laryngeal lesions due to explosions are termed laryngeal blast injuries when they result exclusively from the shock wave effects on laryngeal structures. Their experimental study is very recent and physical and physiopathologic bases for these lesions are discussed in relation to two cases. It is essential to identify these lesions early in all victims of an explosion since their presence may indicate the existence of pulmonary or abdominal blast injuries, detected at a later stage and affecting vital prognosis.

Blast Injuries↗
PubMed1986

[Blast injuries of the ear. Current status and study of 200 cases].

Clinical case-reports of 200 patients with blast-induced lesions are used as a basis for a review of physical and physiopathologic factors. Otologic aspects of injuries due to high-intensity shock waves are discussed and clinical and histopathologic features described. The place of post-traumatic pressure induced injuries to ear in catastrophy medicine is emphasized.

Adolescent↗
PubMed1986

[Major acoustic injuries caused by firearms].

The appearance of new generations of firearms, very harmful for the hearing of the shooter, suggested the need for an updated review of data concerning detonations and their effect on hearing. Emphasis is given to the place of acoustic injuries among traumatic pressure-induced otopathies as well as the value and efficacy of current therapeutic measures.

Ear↗
PubMed1975

[Facial phycomycosis. A propos of 2 cases].

Among deep mycoses, sub-mocosal phycomycosis due to Entomophthora Cornata is of interest to stomatologists as it is mainly located in the middle and lower areas of the face. symptomatology is characterized in general by upper naso-labial deformation the extent of which is dependent on the stage of development reached. The only means of identifying the nature of the lesions is by biopsy which always enables diagnosis of deep mycosis to be made and sometimes, by means of a culture, identification of the agent responsible. This is a lower saprophytic fungus of decaying vegetable and telluric matter. It usually enters the body through the mucous membrane when there is a traumatic fissure. Ingress through the teeth should not be overlooked. Antifungal preparations and reconstructive surgery constitute the treatment early application of which determines prognosis.

Adult↗