1. Use of DPOAEs for assessing hearing loss caused by styrene in the rat
- Author
-
Benoît Pouyatos, Pierre Campo, and R Lataye
- Subjects
Male ,medicine.medical_specialty ,Sensitive index ,Hearing loss ,Otoacoustic Emissions, Spontaneous ,Population ,Deafness ,Audiology ,Sensitivity and Specificity ,Styrene ,chemistry.chemical_compound ,Ototoxicity ,otorhinolaryngologic diseases ,medicine ,Animals ,Rats, Long-Evans ,Evoked potential ,education ,Perceptual Distortion ,education.field_of_study ,Cell Death ,medicine.diagnostic_test ,Chemistry ,Auditory Threshold ,medicine.disease ,Sensory Systems ,Rats ,Hair Cells, Auditory, Outer ,medicine.anatomical_structure ,Evoked Potentials, Auditory ,Solvents ,sense organs ,Hair cell ,medicine.symptom ,Audiometry - Abstract
The study was carried out to test whether or not cubic distortion otoacoustic emissions were more sensitive than auditory-evoked potentials for assessing styrene-induced hearing losses in the Long-Evans rat. For the purposes of comparison, changes in cubic distortion product otoacoustic emissions (DeltaDPOAE), evoked potential permanent threshold shifts (PTS) and outer hair cell losses were measured in a population of styrene-treated rats. Each rat was exposed to either 650 or 750 ppm of styrene for 4 weeks, 5 days per week, 6 h per day. Only the 750 ppm exposure caused significant hearing losses. For this concentration, DPOAEs appeared as sensitive to styrene as the audiometry performed with evoked potentials, but not more. A high coefficient of correlation [0.84< or =r< or =0.91] between DeltaDPOAE and PTS was obtained across the styrene-induced effects for frequencies ranging from 5 to 12 kHz. This experiment demonstrates that DPOAEs can be used to monitor the ototoxicity induced by styrene even though they cannot be considered as a more sensitive index of cochlear pathology than the evoked potentials, at least under our experimental conditions. Likewise evoked potentials, normal DPOAEs may not guarantee a normal cochlear status and therefore results of DPOAE measurements should be interpreted cautiously. The use of both techniques and the determination of the ratio DeltaDPOAE/PTS may be useful in determining the cause of hearing loss: mechanical or chemical process. Moreover, because of its non-invasive and objective characteristics, the use of DPOAEs could play a greater role in a prevention policy.
- Published
- 2002