IEC 60645-6:2009 applies to instruments designed primarily for the measurement of otoacoustic emissions in the human external acoustic meatus evoked by acoustic probe pulses or tones. This standard defines the characteristics to be specified by the manufacturer, lays down performance specifications for two types of instruments and specifies the functions to be provided on these types. IEC 60645-6:2009 describes methods of test to be used for approval testing and guidance on methods for undertaking routine calibration. The purpose of IEC 60645-6:2009 is to ensure that measurements made under comparable test conditions with different instruments complying wit