Auditory inspection time: on the importance of selecting the appropriate sensory continuum

Auditory Inspection Time (AIT) is an index of mental speed which correlates moderately with measures of intelligence. This study shows that a loudness version (APT-L) of an AIT task correlated higher with Raven's Advanced Progressive Matrices (RAPM) than a pitch version (AIT-P). When pitch discrimination ability was partialled out, the correlation between AIT-P and RAPM dropped to 0, while the correlation between AIT-L and RAPM was largely unaffected. The overall pattern of correlations between AIT-P, AIT-L, musical ability, loudness discrimination ability, pitch discrimination ability, and RAPM suggests that AIT-L provides a purer index of mental speed, whereas AIT-P is strongly affected by pitch discrimination ability and musical ability. The results also suggest that the proposed association between sensory discrimination and intelligence might be restricted to the pitch continuum. (C) 1998 Elsevier Science Ltd. All rights reserved.