ITU P.340:2000
ITU P.340:2000 Transmission Characteristics And Speech Quality Parameters Of Hands-free Terminals Describes the generic transmission characteristics of hands-free terminals, whatever the applications or technologies integrated.
Table of Contents
1Introduction2Normativereferences
3Definitionsandabbreviations
4Transmissioncharacteristics
4.1Sendingsensitivity
4.2Receivingsensitivity
4.3Frequencyresponsecurves
4.4Subjectiveevaluationsofloudnessratings
4.5Objectiveevaluationsofsensitivityand
loudnessratings
4.6Switchingparameters
5Testingconditions
5.1Testtable
5.2Testarrangement
5.3Calibrationoftheartificialmouth
5.4Testenvironment
5.5Testsignals
5.6Testsignallevels
6Conversationalquality
7Parametersmeasuredinstrumentally
7.1Attenuationrangea[H]
7.2Attenuationdistributionatidlemode
7.3Hang-overtime
7.4Dynamiccompression
7.5Reverberance
7.6Time-dependenttransferfunction
7.7Duplexbehaviour
7.8Controlcharacteristicsofechocancellation
7.9Speechdetection
7.10Speechdetectionwithambientnoise
7.11Backgroundnoisetransmission
8Behaviourofhands-freeterminalsindoubletalk
situation
8.1Categorization
8.2Terminalcouplinglossindoubletalksituation
9ParameterstobeevaluatedforeachtypeofHFT
10Acousticechocontrollersandspeechenhancement
devices
10.1Functionalunits
10.2Delay
10.3Acousticechocontrolspecifications
AnnexA-Testresults
A.1Categorizationofhands-freeterminalsbasedon
doubletalkperformance
A.2RelationshipbetweenListeningonlytests,Double
talktestsandConversationtests:comparisonof
sixdifferenthands-freeterminals
AppendixI-Preliminaryvalues
I.1Doubletalkperformance
I.2Build-uptimecharacteristics
I.3LeveladjustmentsbycompandingorAGC
AppendixII-Examplesofprocessingdelaysformobile
hands-freeterminal
II.1Example1
Tadd_proc(additionaltimeforprocessing)
II.2Example2
AppendixIII-Recommendedtestbed
III.1Example1:Implementedtesthybrid
III.2Example2:AdaptiveEchoCanceller
AppendixIV-Bibliography