Sound field and sound absorption
Concentric propagation of sound waves. The lines of the same loudness are shown which decreases as the distance to the sound source increases.
Sound propagates from its source in a circular way, the sound energy spreads over an increasingly large area and the sound pressure decreases accordingly.
In a free sound field it decreases by about 6 dB every time the distance to source is doubled. Within a room, however, this only applies very close to the sound source.
Information and ideas:
Useful for discussing why we hear less the further away the sound source is.
Relevant for teaching:
Vibrations and waves
Communication and understanding