The speech‐to‐song illusion.

This paper reports the first formal investigation of a surprising illusion: A particular spoken phrase is made to be heard convincingly as sung rather than spoken, simply by repeating it several times over. Three groups of 18 subjects each listened to the spoken phrase repeated ten times, and they judged after each repetition whether, and how strongly, they heard the phrase as spoken or as sung. For all groups, the first and last repetitions were identical. For the first group, the intervening repetitions were also identical. For the second group, the intervening repetitions were transposed upward and downward slightly (by 2/3 semitone and 1 1/3 semitone), so that the pitches differed but the pitch relationships were preserved. For the third group, the intervening repetitions consisted of the untransposed syllables presented in jumbled orders. Comparing the first with the last repetition, a clear and highly significant transition from perceived speech to perceived song occurred when the intervening repeti...