Paper accepted in the Journal of the Acoustical Society of America
Be on the lookout for "The effects of variability on context effects and psychometric function slopes in speaking rate normalization", which was just accepted for publication in The Journal of the Acoustical Society of America. Previous research (including some of our own) has examined how different sources of acoustic variability interfere with spectral context effects in speech categorization; here similar questions are asked in temporal context effects (TCEs, a.k.a. speaking rate normalization). Beginning with the traditional trial format of a context sentence followed by a target word, here we demonstrate that variability in sentence contents as well as variability in talker each interfere with these context effects, resulting in smaller perceptual shifts (a slowly spoken context sentence making the target sound as though it has a shorter / voiced VOT; a quickly spoken context sentence making the target sound as though it has a longer / voiceless VOT). Matching the variability in speaking rates themselves levels the playing fields somewhat, but even when all of these conditions tested a single slow speaking rate and a single fast speaking rate, other uncontrolled acoustic variability still interferes with context effects. Therefore, acoustic variability has different impacts on spectral and temporal context effects, seemingly closely tied to their neural mechanisms proposed to underlie each effect.