a primer in sound for architects
The starting point is always the sounds that are actually produced in a room - the activity, the use - since the acoustic affects the activity, and different activities demand different acoustic environments.
Room sizes are in much the same size range as audible sounds, (about 20m-2cm) so room design has a very direct influence on experienced sound. Since space is aural, much of the delight in creating rooms has always been aural.
In an enclosed space, sounds will linger before dying away, a phenomenon called reverberation.
Sound will also be focused, reflected, and 'shaped' by the geometry of the space. Since the smaller sounds (higher frequencies) are more directional, this directional property is more keenly felt with smaller sounds.
Acoustic properties apply to all types of space, from small, absorbent spaces such as a bedroom, to large reverberant spaces such as a railway concourse. Outdoor spaces such as forests are also quite reverberant, and often one will encounter focusing and special effects such as arches and vaults. The architect should deploy these things carefully and animate the spaces with sound.