Rec. ITU-T P.37 (03/1993) … COUPLING HEARING AIDS TO TELEPHONE SETS
FOREWORD
CONTENTS
INTRODUCTION
1 Magnetic field strength around the earcap of telephone handsets which provide for coupling ...
    1.1 Introduction
    1.2 Scope
    1.3 Explanation of terms
    1.4 Magnetic field strength measurements and recommended values
    1.5 Probe coil
2 Characteristics of telephone sets that provide additional amplification for the benefit of hearing ...
    2.1 Introduction
    2.2 Sending characteristics
    2.3 Receiving characteristics
    2.4 Sidetone
Annex A … Measurement of an acousto-magnetic adapter generating a magnetic field
A.1 Scope
A.2 Definition of the adapter plane
A.3 Definition of the plane of measurement
A.4 Measurement procedures
A.5 Magnetic field requirements
A.6 Physical properties
Bibliography