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     General description    
 6     Physical characteristics             
        6.1     General rules     
        6.2     Pin assignments
 7     Electrical interface specification             
        7.1     Communication mode   
        7.2     Multimedia playback (provisional, for further study)              
 8     Headset specification
        8.1     Communication mode   
        8.2     Multimedia playback mode (provisional, for further study)   
 9     Function requirements for terminals with the universal headset interface      
Annex A – Interpolation method for diffuse-field correction    
Appendix I – Audio connectivity for sockets with four contact points    
        I.1     2.5 mm diameter plug connector with four poles       
        I.2     2.5 mm diameter socket connector with four contact points  
        I.3     3.5 mm diameter plug connector with four poles       
        I.4     3.5 mm diameter socket connector with four contact points  
Appendix II – Audio connectivity for sockets with four contact points (optional dimensions to accommodate terminal designs with curved edges)    
       II.1     2.5 mm diameter plug connector with four poles      
       II.2     3.5 mm diameter plug connector with four poles      
Appendix III – Audio connectivity for sockets with three contact points    
      III.1     2.5 mm diameter plug connector with three poles    
      III.2     2.5 mm diameter socket connector with three contact points
      III.3     3.5 mm diameter plug connector with three poles    
      III.4     3.5 mm diameter socket connector with three contact points
Appendix IV – Other considerations    
       IV.1     Filter recommendation  
       IV.2     ESD   
       IV.3     Microphone basics – background               
       IV.4     Vcc Voltage for microphone bias
       IV.5     DC resistance of microphone       
Bibliography