Overview

The background noise levels in recording studios, control rooms, and listening rooms must be kept under control if these rooms are to be of maximum use in their intended way. Hums, buzzes, rumbles, aircraft noises, tooting auto horns, dogs barking, or typewriter sounds are most incongruous if audible during a lull in a program. Such sounds might not be noticed outside the studio when they are a natural part of the situation, but during a pause or a quiet musical or speech passage they stand out like the proverbial sore pollex.

In a studio, interfering sounds can come from control-room monitors operating at high level or from equipment in adjacent areas. Control rooms have their own noise problems, some intruding from the outside, some generated by recorders, equipment cooling fans, etc. There is one source of noise, however, that is common to all sound-sensitive rooms, and that is the noise coming from the air-conditioning diffusors or grilles, the subject of this chapter. A certain feeling of helplessness in approaching air-conditioning noise problems is widespread and quite understandable.

The control of air-conditioning noise can be expensive. A noise specification in an air-conditioning contract for a new structure can escalate the price. Alterations of an existing air-conditioning system to correct high noise levels can be even more expensive. It is important for studio designers to have a basic understanding of potential noise problems in air-conditioning systems so that adequate control and supervision can be exercised during planning stages and installation.