1
Scope
2 References
3 Definitions and abbreviations
3.1 Definitions
3.2 Abbreviations
4 Sending Loudness Rating (SLR) and
receiving Loudness Ratings (RLR)
5 Sidetone Masking Rating (STMR) and
Listener Sidetone Rating (LSTR)
6 Sending and receiving frequency
responses
7 Noise characteristics at sending
and receiving
8 Distortion characteristics at
sending and receiving
8.1 Method 1 (Noise method)
8.2 Method 2 (Sinewave method)
9 Out-of-band signals
9.1 Sending
9.2 Receiving
10 Weighted Terminal Coupling Loss (TCLw)
11 Stability loss
12 Delay
13 Input versus output (amplitude) characteristics
Annex A – Variation
of gain with input level
A.1 Sending direction
A.2 Receiving direction
Annex B – Objective
measurement methods for testing
B.1 Introduction
B.2 Approaches for testing digital telephones
B.3 Definition of 0 dB reference point
B.4 Definition of interfaces
B.5 Codec specification
B.6 Measurement of digital telephone
transmission characteristics
Annex C – Distortion
allowances
Annex D – Test
equipment requirements
D.1 Electro-acoustic equipment
D.2 Test signals
D.3 Accuracy of test equipment
Appendix
I – Bibliography