Loudness patterns approximate specific loudness by ignoring the lower slope entirely.

Evidence

In order to simplify the procedure for ordinate values, only the main specific loudness and the upper slope of the specific loudness are used in the procedure; the specific loudness towards lower critical-band rates is ignored. Therefore, the shape of the specific loudness, which is produced by a tone or by a narrowband noise, is approximated by three parts. It starts with a vertical rise up to the third-octave band level measured, comes to a main value corresponding to the third-octave band level in question and rises again vertically for the next higher third-octave band, if its level is larger than that of its neighbouring lower third-octave band. If the next higher third-octave band level is lower, the decrease towards higher centre frequencies follows the broken lines, corresponding to the upper slope of specific loudness. This way, the final specific loudness versus critical-band rate pattern, shortened to “loudness pattern” , is determined and indicated by the highest thick solid lines in Fig. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1312

Categorization

• DEFINE: Defines the ‘loudness pattern’ construction and its simplifying three-part approximation, ignoring lower-slope specific loudness.