Rec. ITU-T P.1150 (01/2020) In-car communication audio specification
Summary
History
FOREWORD
Table of Contents
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
7 Test arrangement
     7.1 Zones and measurement paths
     7.2 Talker-listener combinations under test
          7.2.1 Adjacent zone testing
          7.2.2 Testing driver and all zones
     7.3 Test arrangement in a car
          7.3.1 Introduction
          7.3.2 Artificial mouth
          7.3.3 Artificial ears
     7.4 ON/OFF control
     7.5 ICC setting
     7.6 Side information
8 Test signal and signal levels
     8.1 Speech signals
          8.1.1 Speech material
          8.1.2 Lombard effect with activated ICC
          8.1.3 Lombard effect with deactivated ICC
          8.1.4 Convergence sequence
          8.1.5 Short speech signal
          8.1.6 Double talk signal
     8.2 Background noise
          8.2.1 Recordings and test set-ups
               8.2.1.1 Reproduction option 1
               8.2.1.2 Reproduction option 2
          8.2.2 Recommended test conditions
     8.3 Removal of competing signals by time-domain subtraction
     8.4 Other test signals
          8.4.1 Maximum-length sequence
          8.4.2 Stability test signal
     8.5 Calculation of signal-to-noise ratio, speech and noise level
9 Measurement parameters and requirements for ICC
     9.1 Stability
          9.1.1 Requirements
          9.1.2 Test methodology
     9.2 Delay
          9.2.1 Introduction
          9.2.2 Reinforcement delay
               9.2.2.1 Requirements
               9.2.2.2 Test methodology
          9.2.3 Self-hearing delay
               9.2.3.1 Requirements
               9.2.3.2 Test
     9.3 Speech Intelligibility
          9.3.1 Introduction
          9.3.2 Requirements
          9.3.3 Test methodology
     9.4 Listening effort
          9.4.1 Requirements
          9.4.2 Test methodology
     9.5 Talker localization accuracy
          9.5.1 Requirements
          9.5.2 Test methodology
     9.6 Adaptive reinforcement
          9.6.1 Requirements
          9.6.2 Test methodology
     9.7 Signal-to-noise ratio
          9.7.1 Introduction
          9.7.2 Requirements
          9.7.3 Test methodology
     9.8 Speech quality
          9.8.1 Requirements
          9.8.2 Test methodology
     9.9 Double talk attenuation
          9.9.1 Requirement
          9.9.2 Test methodology
     9.10 Media Interaction
          9.10.1 Requirements
               9.10.1.1 Media transparency in the presence of ICC
               9.10.1.2 ICC reinforcement in the presence of media
          9.10.2 Test methodology
               9.10.2.1 Media transparency in the presence of ICC
               9.10.2.2 ICC reinforcement in the presence of media
     9.11 Background noise transmission
          9.11.1 Requirements
          9.11.2 Test methodology
Annex A  Standard set of user scenarios
Annex B  Delay calculation via impulse response measurement
Annex C  Delay calculation via cross-correlation
Annex D  Calculations for stability assessment
     D.1 Introduction
     D.2 Spectrum vs time
     D.3 Activity classification
     D.4 Analysis ranges
     D.5 Calculation of stability assessment (energy-present above background)
Annex E  Calculation of separated speech and noise levels
     E.1 Introduction
     E.2 Spectrum vs time
     E.3 Activity classification
     E.4 Estimation of average spectra
     E.5 Speech/noise level and SNR
Appendix I  Details on Lombard speech
     I.1 With ICC reinforcement disabled
          I.1.1 Recommendation
          I.1.2 Supporting evidence
               I.1.2.1 Overview
               I.1.2.2 Data analysis
               I.1.2.3 Results
               I.1.2.4 Conclusion
     I.2 With ICC reinforcement enabled
          I.2.1 Recommendation
          I.2.2 Supporting evidence
               I.2.2.1 Existing data
               I.2.2.2 New study overview
               I.2.2.3 Data collection – intelligibility
               I.2.2.4 Data collection – preference/speech quality
               I.2.2.5 Results on intelligibility
               I.2.2.6 Results speech quality/preference
               I.2.2.7 Conclusion
Appendix II  Guidance for subjective evaluation of system stability
Bibliography