TABLE OF CONTENTS Speech privacy in enclosed and open plans depends on the signal-to-noise ratio between the intruding speech level ( signal) and the steady background sound ( noise). The intruding speech level is largely determined by the voice effort of the speaker (how loud) and the noise reduction between enclosed rooms, or between workstations in the open plan. The background noise commonly is produced by the HVAC system (e.g., airflow noise at terminal devices), office activities, or electronic masking sound systems (see Chap. 7). The acoustical demands usually involve one or more of the following.
Ability to talk without having conversations understood by neighbors
Freedom from distracting intruding noises (usually unwanted nearby conversations)
Allowance for face-to-face conversations ( < 6 ft apart) and telephone conversations to be clearly understood
In enclosed rooms, the major paths for speech intrusion are common walls and doors, flanking such as ceiling plenums, and leaks such as cracks and holes in the intervening constructions. In open plans, the path for speech intrusion is direct, or interrupted only by partial-height barriers (called screens). Sound travels from speaker to listener directly; by diffraction over and around partial-height barriers; and by reflection from ceiling, partial-height barriers, walls and other vertical surfaces.
As is the situation with most acoustical problems, speech privacy can be analyzed in three parts: source, path, and receiver. The source is the speaker (talker) and the receiver is the person desiring privacy from intruding conversations. The paths are direct...
