Analog Box 2 : Audio Research : Temporal Coherence : Part 3.1

Temporal Coherence in the Perception of Tone Sequences

Part 3.1
Pitch or Spectral Components

In this and the following part we will investigate whether contiguity of pitch or of spectral components in complex tones determines the phenomena of temporal coherence and fission.

Load example circuit for part 3.1

In a fast alternating sequence of a pure tone and a complex tone of the same pitch but without any contiguous frequency components, we hear not temporal coherence but fission. In this circuit the complex tone B is the sum of the harmonics 3 through 10 of the fundamental 200 Hz, which is, however, itself not present in the complex tone.

On the other hand with the proper amplitude of the pure tone A, you will hear the temporal coherence between the pure tone and a component of the complex tone, when they are contiguous in frequency. This effect seems to double the tempo of the pure tones. Move the pure tone by changing its frequency along the lower harmonics of the complex tone and listen to its tempo.