Читать книгу Engineering Acoustics - Malcolm J. Crocker - Страница 168

The term loudness adaptation refers to the apparent decrease in loudness that occurs when a subject is presented with a sound signal for a long period of time [45]. The effect has been studied extensively by presenting tones for an extended period of time to one ear and then allowing the subject to adjust the level of a second comparison tone of the same frequency to the other ear. Such experiments have demonstrated that loudness adaptation of as much as 30 dB can be observed for very quiet sounds below 30 dB and much less for louder sounds of the order of 70 dB. However, other research has shown that loudness adaptation is reduced or even absent when binaural interactions are minimized. Recent research has shown that loudness adaptation is quite complicated. It varies from person to person. More adaptation occurs for very quiet sounds of about 30 dB and for high‐frequency tones than for low‐frequency tones or noise [19]. This phenomenon is obviously of interest to those concerned with sounds such as interior vehicle noise, that people experience over an extended period.