Effect of noise on word discrimination by subjects with impaired hearing, compared with those with normal hearing

A comparison was made of the discrimination ability of different groups of hearing-impaired and normal-hearing subjects in noisy conditions. Four groups of subjects having a sensorineural hearing loss with various audiogram configurations, one group of subjects having a conductive hearing loss and one group of normal-hearing subjects were chosen. The submaster tapes were recorded in quiet and in pink noise with signal-to-noise ratios of -3, -8, and -13 dB. The test subjects heard the test words monaurally via earphones. The best speech discrimination was achieved in quiet, anechoic conditions. As the noise level increased, speech discrimination decreased. Subjects with sensorineural hearing loss were more adversely affected by noise than subjects with normal hearing or with conductive hearing loss. However, at high noise levels, their speech discrimination was poorer than that of normal-hearing subjects. Persons with a high-frequency hearing loss, cut-off point 1 kHz, suffered in noise similarly to those with sloping or flat hearing losses. In quiet and in moderate noise, the speech discrimination of subjects with a conductive hearing loss and subjects with normal hearing was similar, while at high noise levels, subjects with conductive hearing losses achieved better discrimination than normal-hearing subjects.