Grey's experiment

Grey's two (2) psychological distance measurements:

1. judgement of timbral similarity:
   d = 1/similarity
2. accuracy in associating specific names to notes:
   d $\propto$ number of confusions

Stimulus notes were

1. equalized for pitch, loudness, and duration;
2. synthesized from recording, allowing for:
   • alteration of frequency, amplitude, and duration.
   • known physical properties (synthesis parameters);
   • control over complexity of physical makeup.

Grey's experiment consisted of:

• 35 data sets (musical subjects)
• 16 different instrument recordings player:
  • E-flat (above middle C)
  • duration 280-400 ms
  • 240 trials: $n(n-1)$ possible pairs of $n=16$ notes.
• listener's similarity ratings:
  1. 1-10: very dissimilar
  2. 11-20: average level of similarity
  3. 21-30: very similar