Low Frequency Noise of Acute Exposure to Bama Fragrant Pig Hair Cell Damage / 听力学及言语疾病杂志

ABSTRACT

Objective To investigate the effect of intense low frequency noise on the different hearing functions and hair cell damage in bama pigs.Methods Thirteen bama pigs were randomly divided into a normal control group (3 pigs) and an experimental group (10 pigs).The pigs in experimental group were randomly divided into 50 Hz subgroup (5 pigs) and 70 Hz subgroup (5 pigs).The 50 Hz subgroup was exposed to intense low frequency noise at 167～170 dB SPL,50 Hz for 30 min,and the 70 Hz subgroup was exposed to intense low frequency noise at 164 dB SPL,70 Hz for 30 min.Auditory brainstem response(ABR) and distortion product otoacoustic emission (DPOAE) were performed before and after noise exposure.The cochlear were collected and the inner ear morphology changes were studied.Results Before the experiment,the ABR threshold of the pig was 20～50 dB SPL,and the average of 50 Hz group was 33.5±9.4 dB SPL,the average of the 70 Hz group was 34.0±4.6 dB SPL.The level of the above 3 000 Hz DPOAE could be elicited.But they were not elicited after the exposure to the noise.The inner ear structures were damaged.The DAPI showed hair cell missing.Conclusion ABR and DPOAE were elevated after noise exposure.The auditory system of bama pigs had irreversible damages.Hair cells damaged were given priority to with necrosis,and the higher the level of intense low frequency noise,the more serious the damage to the hair cell.