CONTENTS

 1     Scope 
 2     References 
 3     Definitions  
 4     Abbreviations   
 5     Experimental design         
        5.1     Speech material     
        5.2     Listening session    
        5.3     Data analysis         
        5.4     Presentation and interpretation of results     
Appendix I – Procedure for proper mixing of speech and noise samples    
        I.1        General 
        I.2        Parameters          
        I.3        Speech and background noise files           
        I.4        Speech and noise input filters        
        I.5        P.56 speech level adjustment        
        I.6        Basic noise level adjustment         
Appendix II – Example of Instructions to subjects