Effects of Four Noise Competitors on the California Consonant Test

Abstract

Thirty-five normal-hearing listeners' speech discrimination scores were obtained for the California Consonant Test (CCT) in four noise competitors: (1) a four-talker complex (FT), (2) a nine-talker complex developed at Bowling Green State University (BGMTN), (3) cocktail party noise (CPN), and (4) white noise (WN). Five listeners received the CCT stimuli mixed ipsilaterally with each of the competing noises at one of seven different signal-to-noise ratios (S/Ns). Articulation functions were plotted for each noise competitor. Statistical analysis revealed that the noise types produced few differences on the CCT scores over most of the S/Ns tested, but that noise competitors similar to peripheral maskers (CPN and WN) had less effect on the scores at more severe levels than competitors more similar to perceptual maskers (FT and BGMTN). Results suggest that the CCT should be sufficiently difficult even without the presence of a noise competitor for normal-hearing listeners in many audiologic testing situations. Levels that should approximate CCT maximum discrimination (D-Max) scores for normal listeners are suggested for use when clinic time does not permit the establishment of articulation functions. The clinician should determine the S/N of the CCT tape itself before establishing listening levels.