CONTENTS

1 Scope
2 Normative references
3 Definitions and abbreviations
3.1 Definitions
3.2 Abbreviations
4 Sending characteristics
4.1 Sending loudness rating
4.2 Sensitivity/frequency response
4.3 Noise
4.4 Harmonic distortion
4.5 Out-of-band signals
5 Receiving characteristics
5.1 Receiving loudness rating
5.2 Sensitivity/frequency response
5.3 Noise
5.3.1 A-weighted
5.3.2 1/3-octave band spectrum
5.4 Harmonic distortion
5.5 Out-of-band signals
6 Echo path loss characteristics
6.1 Terminal coupling loss
6.2 Stability loss
7 Delay
Annex A Test methods
A.1 Electrical interface specifications
A.2 Test conditions
A.2.1 Test room
A.2.2 Test arrangement
A.2.3 Electroacoustic equipment
A.2.4 Test signals
A.2.5 Test signal levels
A.2.6 Accuracy of calibrations
A.3 Transmission requirements testing
A.3.1 Sensitivity/frequency response
A.3.2 Loudness ratings
A.3.3 Terminal coupling loss
A.3.4 Stability loss
A.3.5 Harmonic distortion
A.3.6 Out-of-band signals
A.3.7 Noise
A.3.8 Delay