1 Scope
2 References
3 Definitions
3.1 Terms defined elsewhere
3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 How to use this Recommendation
6.1 Determining compliance with this Recommendation
6.2 Testing at different stages of the development cycle
7 Test arrangement
7.1 Test arrangement in a car
7.1.1 Microphone related simulation
7.1.2 Positioning of the hands-free terminals
7.1.3 Artificial mouth
7.1.4 Artificial ear
7.1.5 Influence of the transmission system
7.1.6 Calibration and equalization
7.1.6.1 Calibration
7.1.6.2 Reference measurement
7.1.7 System simulator settings
7.1.8 Environmental conditions
7.1.8.1 Verification of environmental conditions
8 Digital interfaces for development, debugging and test
8.1 Interfaces and access points
8.2 Test set-up and tests
8.2.1 Recording and insert background noise
8.2.2 Recording and insert near-end speech recordings
8.2.3 One-way speech quality in send direction
8.2.4 Speech distortion in double talk
9 Test signals and test signal levels
9.1 Signals
9.2 Background noise signals
9.2.1 Recording of driving noise
9.2.2 Playback of the recorded background noise
10 Measurement parameters and requirements for microphones used in speakerphone hands-free systems
10.1 Microphone measurements in anechoic conditions
10.1.1 Microphone sensitivity
10.1.1.1 Requirements
10.1.1.2 Test
10.1.2 Microphone frequency response in anechoic conditions
10.1.2.1 Requirements
10.1.2.2 Test
10.1.3 Microphone directional characteristics
10.1.3.1 Requirements
10.1.3.2 Test
10.1.4 Microphone distortion
10.1.4.1 Requirements
10.1.4.2 Test
10.1.5 Maximum sound pressure level
10.1.5.1 Requirements
10.1.5.2 Test
10.1.6 Self-noise
10.1.6.1 Requirements
10.1.6.2 Test
10.2 Microphone measurements in the car
10.2.1 Microphone output level in the car
10.2.1.1 Requirements
10.2.1.2 Test
10.2.2 Overload point
10.2.2.1 Requirements
10.2.2.2 Test
10.2.3 Microphone frequency response in the car
10.2.3.1 Requirements
10.2.3.2 Test
10.2.4 Idle channel noise
10.2.4.1 Requirements
10.2.4.2 Test
10.2.5 SNR improvement (in the car)
10.2.5.1 Requirements
10.2.5.2 Test
11 Measurement parameters and requirements for hands-free terminals
11.1 Preparation measurements
11.2 Delay
11.2.1 Requirements
11.2.1.1 Requirements for systems without SRW
11.2.1.2 Requirements for systems with SRW
11.2.2 Delay in send direction
11.2.2.1 Test
11.2.3 Delay in receive direction
11.2.3.1 Test
11.3 Loudness ratings
11.3.1 Requirements
11.3.2 Test loudness rating in send direction
11.3.3 Test loudness rating in receive direction
11.3.4 Variation of loudness rating in send direction
11.3.4.1 Requirements
11.3.4.2 Test
11.3.5 Variation of loudness rating in receive direction
11.3.5.1 Requirements
11.3.5.2 Test
11.4 Sensitivity frequency responses
11.4.1 Send sensitivity frequency response
11.4.1.1 Requirements
11.4.1.2 Test
11.4.2 Receive sensitivity frequency response
11.4.2.1 Requirements
11.4.2.2 Test
11.5 Speech quality during single talk
11.5.1 One-way speech quality in send direction
11.5.1.1 Requirement
11.5.1.2 Test
11.5.2 One-way speech quality in receive direction
11.5.2.1 Requirement
11.5.2.2 Test
11.6 Listening speech quality stability
11.6.1 Listening speech quality stability in send direction
11.6.1.1 Requirement
11.6.1.2 Test
11.6.2 Listening speech quality stability in receive direction
11.6.2.1 Requirement
11.6.2.2 Test
11.7 Idle channel noise
11.7.1 Idle channel noise in send direction
11.7.1.1 Requirements
11.7.1.2 Test
11.7.2 Idle channel noise in receive direction
11.7.2.1 Requirements
11.7.2.2 Test
11.8 Out-of-band signals
11.8.1 Discrimination against out-of-band signals in send direction
11.8.1.1 Requirements
11.8.1.2 Test
11.8.2 Spurious out-of-band signal in receive direction
11.8.2.1 Requirements
11.8.2.2 Test
11.9 Distortion in send
11.9.1 Requirements
11.9.2 Test
11.10 Distortion in receive
11.10.1 Requirements
11.10.2 Test
11.11 Echo performance
11.11.1 Terminal coupling loss
11.11.1.1 Requirements
11.11.1.2 Test
11.11.2 Echo level vs. time
11.11.2.1 Requirements
11.11.2.2 Test
11.11.3 Spectral echo attenuation
11.11.3.1 Requirements
11.11.3.2 Test
11.11.4 Initial convergence without background noise
11.11.4.1 Requirements
11.11.4.2 Test
11.11.5 Initial convergence with background noise
11.11.5.1 Requirements
11.11.5.2 Test
11.11.6 Echo performance with time variant echo path
11.11.6.1 Requirements
11.11.6.2 Test
11.11.7 Echo performance with time variant echo path and speech
11.11.7.1 Requirements
11.11.7.2 Test
11.11.8 Switching characteristics
11.11.8.1 Activation in send direction
11.11.8.1.1 Requirements
11.11.8.1.2 Test
11.11.8.2 Activation in receive direction
11.11.8.2.1 Requirements
11.11.8.2.2 Test
11.11.8.3 Attenuation range in send direction
11.11.8.3.1 Requirements
11.11.8.3.2 Test
11.11.8.3.3 Test
11.11.8.4 Attenuation range in receive direction
11.11.8.4.1 Requirements
11.11.8.4.2 Test
11.12 Double talk performance
11.12.1 Attenuation range in send direction during double talk: AH,S,dt
11.12.1.1 Requirements
11.12.1.2 Test
11.12.2 Attenuation range in receive direction during double talk: AH,R,dt
11.12.2.1 Requirements
11.12.2.2 Test
11.12.3 Detection of echo components during double talk
11.12.3.1 Requirements
11.12.3.2 Test
11.12.4 Sent speech attenuation during double talk
11.12.4.1 Requirements
11.12.4.2 Test
11.13 Background noise transmission
11.13.1 SNR improvement provided by the HFT algorithm
11.13.2 Background noise transmission after call set-up
11.13.2.1 Requirements
11.13.2.2 Test
11.13.3 Speech quality in the presence of background noise
11.13.3.1 Requirements
11.13.3.2 Test
11.13.4 Quality of background noise transmission (with far-end speech)
11.13.4.1 Requirements
11.13.4.2 Test
11.13.5 Quality of background noise transmission (with near-end speech)
11.13.5.1 Requirements
11.13.5.2 Test
11.13.6 "Comfort noise" injection
11.13.6.1 Requirements
11.13.6.2 Test
12 Verification of the transmission performance of short-range wireless transmission enabled phones
12.1 Interface definition and calibration
12.1.1 SRW delay
12.1.1.1 Requirements
12.1.1.2 Test in send direction
12.1.1.3 Test receive direction
12.2 SRW loudness ratings
12.2.1 Requirements
12.2.2 Test SRW JLR in send direction
12.2.3 Test SRW JLR in receive direction
12.2.4 SRW linearity in send direction
12.2.4.1 Requirements
12.2.4.2 Test
12.2.5 SRW linearity in receive direction
12.2.5.1 Requirements
12.2.5.2 Test
12.3 SRW sensitivity frequency responses
12.3.1 SRW send sensitivity frequency response
12.3.1.1 Requirements
12.3.1.2 Test
12.3.2 SRW receive sensitivity frequency response
12.3.2.1 Requirements
12.3.2.2 Test
12.4 SRW noise cancellation test in send direction
12.4.1 Requirements
12.4.2 Test
12.5 SRW speech quality during single talk
12.5.1 One-way listening speech quality in send direction
12.5.1.1 Requirement
12.5.1.2 Test
12.5.2 Listening speech quality stability in send direction
12.5.2.1 Requirement
12.5.2.2 Test
12.5.3 SRW one-way listening speech quality in receive direction
12.5.3.1 Requirement
12.5.3.2 Test
12.5.4 Listening speech quality stability in receive direction
12.5.4.1 Requirement
12.5.4.2 Test
12.5.5 Verification of disabled echo control
12.5.5.1 Requirements
12.5.5.2 Test
13 Car-to-car communication
14 Guidance on subjective testing
15 Corded headsets
15.1 Connector type
15.2 Connector wiring and electrical specifications
15.3 Headset receive characteristics
15.4 Headset transmit characteristics
15.5 Standard behaviour in the presence of corded headsets
16 Wireless headsets
16.1 Wireless headset types
16.2 Test methodology for verification of standard behaviour
16.3 Standard behaviour in the presence of wireless headsets
16.3.1 Associate headset with vehicle
16.3.2 Enter the vehicle
16.3.3 Receive a call
16.3.4 Make a call
16.3.5 Terminate a call
16.3.6 Exit the vehicle
16.3.7 Listen to other audio source
16.3.8 Switch between other audio and telephony
16.3.9 Intra-vehicle communications
Annex A Speech quality measurements
Annex B Principles of Relative Approach
Annex C Example for a questionnaire for subjective testing
C.1 Performance rating – Overview
C.2 Test categories and rating types
C.3 Speech and background noise quality in send direction
C.3.1 Speech level (office)
C.3.2 Speech level fluctuations
C.3.3 Speech quality/speech naturalness
C.3.4 Intelligibility/listening-effort
C.3.5 Signal-to-noise ratio for near-end single talk
C.3.6 Background noise quality
C.3.7 Noise quality for transient noise sources
C.3.8 Adaptation to background noise
C.4 Speech quality in receive direction (in the car under test)
C.4.1 Speech sound quality/speech naturalness (receive)
C.4.2 Intelligibility/listening-effort (Receive)
C.4.3 Speech level (receive, maximum volume)
C.4.4 Speech level for nominal volume and new call
C.5 Echo cancellation performance
C.5.1 Disturbance caused by echo
C.5.2 Echo intensity
C.5.3 Echo duration
C.5.4 Frequency of echo occurrence
C.5.5 Echo intelligibility
C.5.6 Comfort noise quality (EC test)
C.5.7 Speech level variation during double talk
C.5.8 Intelligibility/listening-effort during double talk
C.6 Hands-free system stability tests (car-to-car)
Annex D Standard set of user scenarios
Annex E System stability with insufficient far-end echo loss
Annex F Microphone related sound field reproduction technique – Multi-point noise simulation method (MPNS)
F.1 Loudspeaker setup in the car
F.2 Microphone setup in the car
F.3 Background noise recordings and reference noise
F.4 Equalization
F.5 Accuracy of the equalization
Appendix I A method to determine the listening speech quality
I.1 One-way speech quality in sending
I.2 One-way speech quality in receiving
Appendix II Reporting template for chapter clause 12 testing
Bibliography