Effects of Noise on NST and NU 6 Stimuli

This study determined how normal-hearing listeners' performance on a nonsense syllable test (NST) was affected by three noise competitors, and how these responses differed from those on the standard NU 6 meaningful word test. Twenty young adult listeners heard the stimuli via earphones and provided verbal responses to the NST and NU 6 items in competition with: white noise, multitalker noise, and white noise which was amplitude modulated by the multitalker noise, each at a 0 dB signal-to-noise ratio. Responses were scored on a whole-word (all-or-none) basis. Statistical analyses revealed that listeners' performance was always poorer on the NST than on the NU 6 regardless of competitor type; and that scores were better in the multitalker noise followed by white noise and amplitude modulated white noise. These data and those from earlier studies indicate that the NST is sufficiently difficult in quiet that it may not warrant testing in noise.