Fletcher-Munsen equal-loudness curves
(frequency response of ears)
An example equal-loudness curve:
Important features to note when looking at Fletcher-Munsen
equal-loudness curves:
- Notice that the curves flatten out at higher loudness levels.
For example in the graph above, the range from highest to lowest in
physical decibel level is about 70 dB; while for the medium loudness
level, the range is 37 dB; and for the highest level, 28 dB.
- Notice that there is an increase in sensitivity to frequency intensity
around 3500&endash;4000 Hz. This is due in part to the first
resonance of the ear canal which is about an inch long. There is a
second resonance at twice the first which can be seen in the medium
loudness level curve at around 8000 Hz.
Source material: