The demonstration of some sound pairs (piano and vocal sound A) used in the second experiment.
Audio
1) the fundamental frequency of vocal sound A is 50 cents lower than that of piano sound (points at uttermost left)
2) the fundamental frequency of vocal sound A is 30 cents lower than that of piano sound (second points from left)
3) the fundamental frequency of vocal sound A is 6 cents lower than that of piano sound (third points from left)
4) the fundamental frequency of vocal sound A is 20 cents higher than that of piano sound (the points at uttermost right)