Subject: Spectral timbre discrimination From: Tom Mercer <T.Mercer04@xxxxxxxx> Date: Fri, 28 Nov 2008 14:30:11 -0000 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Dear list, We have recently completed an auditory memory study using the interpolated tone paradigm (Deutsch, 1970). Our aim was to look at spectral timbre through varying the position of one of the harmonics in the two sounds to be compared. We used a same-different task. Listeners were presented with two tones - A and B - which could be presented in any combination. This created four trial types: AA, BB, AB and BA. Pitch was randomly varied across trials. Tone A featured the fundamental and the fourth, sixth and eighth harmonics, and tone B featured the fundamental, and the fourth, seventh and eight harmonics. So, the only difference between the tones was whether it included the sixth or the seventh harmonic. For example, on an AB trial the sixth harmonic present in tone A would be shifted upward to the seventh harmonic in tone B. Along with uncovering the interference effect we anticipated when certain intervening tones were placed into the interstimulus interval, we also found that participants were much worse on the BA trials (i.e. where the seventh harmonic was shifted down to the sixth harmonic) than on AB trials (where the sixth harmonic was shifted up to the seventh harmonic). We found this effect both during initial training and when the intervening tone was placed into the sequence. Whilst this phenomenon is not the main focus of our study, we would be very interested in trying to understand why this has occurred but so far we have been unable to come across any papers which have found a similar effect. Can anyone recommend any studies which have found related effects to ours? That is, where a certain component change is easier or more difficult to identify than another, particularly in relation to 'upward' or 'downward' shifted harmonics? Any help would be much appreciated. Thanks in advance, Tom Mercer Postgraduate Research Student Institute of Psychological Sciences University of Leeds LS2 9JT Email: T.Mercer04@xxxxxxxx