1
Scope
2 Normative 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)
8.1.1 Sending
8.1.2 Receiving
8.2 Method 2 (Sinewave method)
8.2.1 Sending
8.2.2 Receiving
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.2.1 Direct digital processing approach
B.2.2 Codec approach
B.3 Definition of 0 dB reference point
B.4 Definition of interfaces
B.5 Codec specification
B.5.1 Ideal codec
B.5.2 Reference codec
B.6 Measurement of digital telephone
transmission characteristics
B.6.1 Sending
B.6.2 Receiving
B.6.3 Sidetone
B.6.4 Terminal coupling loss
B.6.5 Stability
B.6.6 Delay
B.6.7 Input versus output (amplitude) 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