DaySequerra NLC5.1ST User Manual
Page 9
NLC5.1ST User Manual
9
Weighting Curves
To achieve a more accurate loudness measurement, the method should include critical bands in the
measurement. Critical bands describe auditory filters within the human cochlea. (J. Allen, 2010). To
illustrate this, a subject is presented with a single tone of a certain energy level, and more tones are
added with equal energy in the critical bands – the total signal energy is kept constant regardless of the
number of tones. If changing from one to two tones, the energy of each of the two tones is exactly half
of that of the single tone. While the amount of audio energy never changes, the perceived loudness
increases as the energy spectrum spreads out across more tones (Johnston, 2006).
J. Allen Cochlea Filters (2010)