Rec. ITU-T P.64 (06/2019) - Determination of sensitivity/frequency characteristics of local telephone systems Summary History FOREWORD Table of Contents 1 Scope 2 References 3 Abbreviations ad acronyms 4 Sending sensitivities of the LTS 5 Receiving sensitivities of the LTS 6 Artificial mouth and voice 7 Artificial ear 8 Definition of sending sensitivity of an LTS 9 Definition of receiving sensitivity of an LTS 10 Definitions of talker and listener side-tone sensitivities of an LTS 11 Methods for determining SmJ, SJe, SmeST, SRNST and (SM Annex A Definitions of mouth reference point and ear reference point Annex B The application of complex terminating impedances when measuring SLR and RLR B.1 Complex impedance terminations B.2 Impedance converter B.3 Differences when measuring a telephone set with a complex impedance using 600 ohm terminations Annex C Definition of the speaking position for measuring loudness ratings of handset telephones C.1 Geometry defining a speaking position C.2 Geometry defining a change in speaking position C.3 Simplification through the use of the position of the ear reference point C.4 Vector representation of the reference points Annex D Definition of handset positions for measuring loudness ratings and frequency responses using the ITU-T P.57 type 3.4 artificial ear on HATS D.1 General D.2 Definition of the standard handset position D.3 Definition of the flat handset position D.4 Definition of the alternative handset position for measuring loudness ratings and frequency responses using the ITU-T P.57 type 3.4 artificial ear on HATS D.5 Definition of the alternative handset position for handsets without a traditional ear cap using the ITU-T P.57 type 3.4 artificial ear on HATS Annex E Definition of handset positions for measuring loudness ratings and frequency responses using the ITU-T P.57 types 3.2 and 3.3 artificial ear on HATS E.1 Definition of standard handset position for measuring loudness ratings and frequency responses using the P.57 types 3.2 and 3.3 artificial ear on HATS E.2 Definition of the alternative handset position for measuring loudness ratings and frequency responses using the ITU-T P.57 type 3.3 artificial ear on HATS E.3 Definition of the alternative handset position for handsets with non-traditional earpiece design using the ITU-T P.57 type 3.3 artificial ear on HATS Annex F Correspondence between measurements using the LRGP and the HATS position Bibliography