What Happens When
fD approaches
fCR
In summary then, When
f
surpasses the so called limit of frequency discrimination
fD,
we distinguish two separate tones. However at that
limit the sensation of roughness still persists, especially in the low pitch
range. Do not confuse
fD
with the limen of frequency discrimination,
the JND for pitch.
Only after surpassing a still larger frequency difference
fCR called
the critical band, the roughness sensation disappears and both tones sound
smooth. This transition from roughness to smoothness is gradual.