CONTENTS

 1     Scope
 2     Normative references
 3     Definitions and abbreviations
 4     Loudness rating parameters for telephone sets
 5     General algorithm for loudness rating calculations
 6     Calculation of SLR and RLR
 7     Calculation of STMR
 8     Calculation of LSTR
Annex A – Fundamental principles of loudness rating calculations
        A.1     Introduction
        A.2     Definitions and symbols concerning sound pressures, sensitivities and transmission losses
                  A.2.1     Concerning talking
                  A.2.2     Concerning listening
                  A.2.3     Concerning telephone or reference connections
        A.3     Structure of the theoretical model
                  A.3.1     Definitions concerning loudness, its relationship to sensation level and loudness ratings
                  A.3.2     Loudness model
        A.4     Values of the parameters
                  A.4.1     General
                  A.4.2     Theoretical derivation of G
                  A.4.3     Determination of values for G
        A.5     Calculation of loudness ratings
                  A.5.1     Deviation of formulas and W weights
Annex B – Fundamental principles of calculation of sidetone masking
        B.1     Calculation from first principles
        B.2     Calculation of STMR using W weights
        B.3     Comments on sealed versus unsealed conditions for the calculation of STMR
        B.4     Calculation of LSTR using W weights
Annex C – An alternative form of the loudness rating algorithm
Annex D – Weighting coefficients for the band 100-8000 Hz
Annex E – Calculation of the listener's sidetone factor D
        E.1     General
        E.2     Non-linear microphones and/or circuitry
        E.3     Linear microphones and circuitry
Annex F – Computation of the sidetone sensitivity S_meST
Annex G – Wideband loudness rating algorithm
Appendix I – Bibliography