[Combined use of glucose and rest period between noise exposure to reduce noise--induced hearing loss].

This paper reports the way which protects hearing from harmful effects of noise. 67 guinea pigs were divided into four groups, 8-9 guinea pigs in each group. The total time of noise exposure at 125 dB SPL white noise in each group was one hour. The control was exposed continuously for 1 hour. Group I was exposed to noise for 30 minutes after intraperitoneal injection of glucose at 2 mg/g body wt., then rest for 30 minutes and exposed for 30 minutes again. Group II was exposed continuously to noise for 1 hour after intraperitoneal injection of glucose at 2 mg and 4 mg/g body wt. Group III was exposed to noise for 30 minutes, rested for 30 minutes and exposed for 30 minutes again without glucose injection. The auditory brain stem response (ABR) was measured before, immediately, 3 days, and 7 days after noise exposure. The effect on hearing conservation was evaluated according to ABR threshold. We observed that the auditory threshold in group I was significantly lower than that of the control in the given time after noise exposure (P less than 0.05), but not so in group II and III. Combined use of glucose and rest period between noise exposure was able to decrease the threshold shift by 15 dB and 10 dB immediately and 7 days after noise exposure respectively.