Abstract:
For large audience spaces such as arenas and stadiums, it is often difficult to satisfactorily control the unoccupied reverberation period of the space because of the large volume in relation to the area of surfaces that are available for the practical installation of sound-absorbing material; and when chairs are of the plastic ``stadium chair'' type, it may be impossible to achieve a suitable stabilization of the reverberation period between unoccupied and occupied conditions. Of course, the use of chairs with sound absorbing upholstery is of major benefit in resolving these problems, but it is frequently found that ``hard'' chairs are selected for maintenance and cost reasons, and in spite of resulting acoustical conditions. However, this situation can be at least partially remedied by installing sound-absorbing material beneath each chair seat as an integral part of the chair construction. Laboratory sound absorption data, obtained in association with a major chair manufacturer, and field data obtained for a multipurpose arena indicate that this is a useful technique which can be applied when ``hard'' chairs are to be used for reasons not relating to acoustics.