scope:

1.1 This International Standard specifies methodology for qualifying acoustic spaces as anechoic and hemianechoic spaces meeting the requirements of a free sound field. 1.2 This International Standard specifies discrete frequency and broadband test methods for quantifying the performance of anechoic and hemi-anechoic spaces, defines the qualification procedure for an omnidirectional sound source suitable for free-field qualification, gives details of how to present the results, and describes uncertainties of measurement.