ABSTRACT
Objective To analyze the test results of persons with noise -induced hearing loss using disyllabic Mandarin speech test materials (MSTMs) .Methods 57 subjects with noise -induced hearing loss (noise group) were divided into three groups according to the duration of noise exposure :less than 10 years ,between 11 and 20 years and more than 20 years ,and also separated into 2 groups in terms of the degrees of hearing loss (group A :pure tone average thresholds of 0 .5 ,1 ,2 ,and 4 kHz less than or equal to 30 dB HL ,group B:pure tone average threshold of 0 .5 ,1 ,2 ,and 4 kHz greater than 30 dB HL) .66 subjects with normal hearing were in the control group .All the subjects enrolled in this study could speak Mandarin well in their daily life .Nine lists of disyllabic Mandarin speech test materials were utilized to test SRT and P -I function for these groups respectively .Results PTA and SRT in the noise group were much higher than the control group ,the average slope of P -I function was 5 .94% /dB ,and the curve of P-I function moved to the right side .SRT showed obvious changes as the increase of the years of noise exposure and especially in the group which had more than 20 years noise exposure (P<0 .01) . SRT of group B which had more hearing loss were greater than that of group A (P<0 .01) .Conclusion SRTs in the noise group are much higher than the control group with the average slope of P -I functions decreasing and the curve moving to the right side .As the years of noise exposure increase and the degrees of hearing loss become more severe ,SRT rise more apparently .
ABSTRACT
OBJECTIVE@#To valuate test results of normal hearing persons with different ages using disyllabic mandarin speech test materials (MSTMs). Obtaining speech recognition threshold (SRT) and P-I function of different ages as clinical reference of hearing recovery and individual's ability to perceive and process speech.@*METHOD@#One hundred and twenty subjects with normal hearing who speak mandarin well in their daily lives were enrolled in this study and divided into four groups (18-30, 31-40, 41-50 and 51-60 years old). Nine lists of disyllabic mandarin speech test materials with equal difficulty were utilized to test each age group.@*RESULT@#There are good agreement between SRT and mean PTA thresholds (at 0.5, 1.0, 2.0, and 4.0 kHz) in each age group. PTA thresholds have little change as age increasing in age group 18-30, 31-40 and 41-50 (P > 0.05). PTA threshold of age group 51-60 increases more apparently compared with the other three groups (P < 0.01). SRT thresholds of each age group increase as age increasing (P < 0.05) and SRT threshold of age group 51-60 increases more apparently (P < 0.01). Slopes of P-I function in each age group are 5.8%/dB, 4.7%/dB, 3.8%/dB, 2.9%/dB respectively.@*CONCLUSION@#Nine lists of disyllabic MSTMs were used to test normal hearing persons in different ages and SRT and P-I function of four different age groups were obtained. As age increases, SRT increases and slope of P-1 functions decreases. PTA and SRT thresholds of age group 51-60 increase more apparently. The SRT and P-I functions provide reference data of normal hearing for utilizing of disyllabic mandarin speech test materials clinically.