Chandler Archbell: Acoustics through the art of poetry

Sound.

A manifestation of itself,

it forms through waves

within the air.

Pressure changes

and deviates from the average

like hipsters in the streets.

They cause a motion,

they make a noise.

Chandler Archbell, 2014

As this prolific poem accurately explains, sound is the product of waves caused by rapid variations of pressure in the air.  These waves push and pull on air molecules, forming what are called compressions and rarefactions (similar to the peaks and troughs of normal waves).  Sound waves coming from a source either go directly into the listener's ear or reflect off surfaces and create reverberation.  Reverberation is a stream of continuing sound created when sound waves constantly reflect off surfaces after the original sound is produced.  The reverb time is the amount of time it takes for the frequency of reverberations to drop below perception level.  Because of their size, concert halls and theaters usually have a long reverb time.

Acoustic panels work best when they don't have any cover or finish that interferes with the acoustical infill or substrate.  They should be positioned to allow the sound to reflect evenly throughout the theater.  Here's a helpful image:

This sexy wood is brought to you by the National Theater of Bahrain.  The architects used wood due to its acoustically reflective surface, which allows sound to spread easily throughout the large space.  The shape of the interior shell also directs sound where it needs to go.  The theater space is also completely soundproof, and it exists as a separate entity from the rest of the building.

Dat separation.