DTMF (Dual Tone Multiple Frequency) tone Frequencies

DTMF frequencies   [Touch-Tone (r)]                                   
                                                                                       
                               High Tone                                       
           hz         1209    1336   1477   1633                                                  
               697         1      2       3         A                                 
          Low  770     4      5       6         B                                 
         Tone  852     7      8       9         C                                 
                   941     *      0       #         D