Room Acoustics, Continued

Countering the

Increasing the Signal-to-Noise Ratio:

Effects of

Intelligibility degradation from reverberation is essentially a signal-to-noise issue, however

Reverberation,

when the noise is specifically caused by reverberation it is referred to as the “Direct-to-

(continued)

 

Reverberant” ratio. Increasing the direct sound field at the listener improves the direct to

 

reverberant ratio and therefore the signal-to-noise ratio. You can increase the direct sound in

 

several ways:

 

1. Move the speaker closer to the listener and reduce the wattage of the speaker:

 

This places the sound where it is needed and minimizes excitation of the room’s

 

reverberation, at the expense of additional speakers.

 

2. Increase the speaker density and reduce the wattage to each speaker:

 

This increases the direct sound heard by the listener by creating overlapping regions

 

of coverage.

 

3. In areas with high ceilings, specify a more directional speaker:

 

A speaker that is more focused (has a higher “Q”) concentrates most of the sound energy

 

in a tighter beam than low “Q” devices. This is important in areas with high ceilings to

 

reduce the effect of multiple late arriving sounds.

 

Note: See the section later in this chapter entitled “Speaker Dispersion Angle and ‘Q’”

 

for more information.

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Tyco 579-769 specifications Areas with high ceilings, specify a more directional speaker