Critical bandwidth marks the point where noise loudness begins to grow with bandwidth

Evidence

The data of Fig. 8.7 indicate clearly that the dependence of loudness on the bandwidth of band-pass noise follows two different rules: one rule indicates independence of bandwidth at small bandwidths, and only holds up to a characteristic bandwidth. The other rule holds for bandwidths beyond that characteristic bandwidth, and indicates that loudness increases with increasing bandwidth. The characteristic bandwidth that separates these two regions from each other is the critical bandwidth which amounts to 160 Hz at a centre frequency of 1 kHz. The results of comparable measurements for different centre frequencies show that the characteristic bandwidth agrees with the critical bandwidth measured using other methods. This means that critical bandwidth plays a very important role in loudness sensation. Actually, results of measurements such as those described in Fig. 8.7 for different centre frequencies, have been used to define critical bandwidth. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1204

Categorization

• DEFINE: Establishes the operationally distinct definition of critical bandwidth via loudness growth that cross-validates other measurement methods.