Interlist equivalency of the CID W-22 word lists presented in quiet and in noise

The interlist equivalency of the CID W-22 word lists administered in quiet and in a background of noise was investigated using 48 normal-hearing subjects. All four word lists were administered at 20 dB SL in quiet and in the presence of a multi talker babble (0 dB signal-to-noise ratio). In the statistical analyses, word performance and subject performance were used as the dependent measures. The results indicated that: (1) the lists are equivalent when administered in quiet; (2) the lists are not equivalent when administered in a background of multi talker babble; (3) the addition of noise changes the relationship among the word lists in a non predictive manner; and (4) the addition of noise changes the level of difficulty of some words of each list to a greater degree, relative to the other words. The results are discussed relative to their implications for hearing evaluation and hearing aid evaluation procedures.