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 mode     
 8     Headset specification           
        8.1     Communication mode               
        8.2     Multimedia playback mode     
 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     Electrostatic discharge              
       IV.3     Microphone basics – background        
       IV.4     Vcc voltage for microphone bias          
       IV.5     DC resistance of microphone 
Bibliography