Limits for Stage Machinery Noise

Limiting noise to appropriate levels is especially challenging in the design of theaters and opera houses as background noise requirements have to be met even during the operation of stage machinery. Although the acoustic requirements of such venues have reached to some maturity and are available in literature these limits consider steady-state noise conditions that are not applicable to the non-steady-state operation of stage machinery during the performance. Oftentimes, the tenders rely on such requirements, which unnecessarily increase the costs for the developer. This raises the question which stage machinery noise levels can be considered acceptable under realistic conditions. To answer this question sound level measurements were conducted during the live performance in German opera houses and speech theaters. This presentation will discuss different analysis strategies of measured data and identify frequency dependent limits for stage machinery noise that are suitable for different types of performances, e.g. opera, ballet or speech theater. Based on these limits the design of stage machinery can be more economical while achieving better acoustic quality at the same time.