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Home > About NLS > Other Writings > Art and Science of Audio Book Production > Host Environments
Issued September 1995
A host environment is the site in which an enclosure used as a narration environment is located. Host environment size can vary from a small area that accommodates only one enclosure to a large area that accommodates several enclosures.
A quiet host environment is important because it protects enclosures used as
narration environments from outside noise. It is also the work site for monitors
and frequently the work site for reviewers. The task of monitoring and reviewing
requires continuous, concentrated attention to acoustical details, and
noise in the host environment affects how well that task can be accomplished.
The host environment should be free from airborne noise and structure-borne
noise. Airborne noise is noise that travels between two locations through the
atmosphere. Structure-borne noise is vibration that travels between two locations
through structural components of the building, such as beams and
girders, and radiates from the floor, walls, and ceiling into the atmosphere
as airborne noise.
Among the most common sources of airborne noise in host environments are ballasts in fluorescent light fixtures, air diffusers, and ventilation ducts. Among the most common sources of vibration in buildings from which structure-borne noise can originate and from which the host environment should be isolated are elevators, central air handling equipment, and boiler rooms.
A host environment must have a floor that is level, firm, and well supported and must provide adequate clear space for each enclosure. Clear space is the distance between any vertical surface in the host environment and the greatest protrusion on the side of an enclosure. Examples of vertical surfaces in a host environment are walls, support pillars, or other enclosures. An example of a side protrusion is a side-mounted fan silencer. The following clear space should be available for each enclosure in a host environment:
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Posted on 2006-02-24