Tyco 579-769 specifications Recommendations for Maximizing System Intelligibility

Recommendations for Maximizing System Intelligibility

Maximizing	Use the following recommendations to maximize system intelligibility:
Intelligibility
	• Ensure at least an 8 dBA signal-to-noise ratio with regard to the speech signal.
	Note: This can result in a higher than 15 dB signal-to-noise ratio for notification tones. If
	the notification tones become too loud for a particular location, consider reducing the volume
	of the tone with respect to the speech signal.
	• Ensure adequate direct sound field coverage for the type of space. Speaker layout pattern
	selection is critical in providing sufficient coverage at a reasonable cost. In areas with high
	reverberation times it is possible to improve intelligibility by decreasing the separation
	between the loudspeakers and the listeners. This increases the ratio of direct to reverberant
	sound and improves intelligibility, but usually requires more loudspeakers to provide the same
	level of coverage.
	• Improve signal-to-noise ratio by putting speakers where people are located. This assures
	good coverage and minimizes stray acoustical that adds to reverberation without contributing
	to intelligibility. In rooms with high ceilings, the areas near the edge of the room can be
	covered more effectively with wall mount speakers.
	• In areas with high ceilings, directional speakers should be selected to avoid multiple speaker
	interactions.
	• Care must be taken to avoid signal distortion. It is critical to ensure that signal levels are
	properly adjusted so that signal distortion does not occur. Properly installed and maintained
	emergency voice/alarm communications systems deliver low distortion by design.
	• Apply acoustic treatments to reduce reverberation.

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