Читать книгу Engineering Acoustics - Malcolm J. Crocker - Страница 122

In a confined space there will be reflections, and far from the source the reflections will dominate. We call this reflection‐dominated region the reverberant field. The region where reflections are unimportant and where a doubling of distance results in a sound pressure drop of 6 dB is called the free or direct field (see Figure 3.18).

Figure 3.18 Sound pressure level in an interior sound field.