The Vista M22 audio processor brings superior sound-quality, acoustic protection and compatibility with those telephones that do not allow direct connection of headsets. Poly H-Top QD Headsets.
 
The Vista M22 audio processor delivers precise levels of listening comfort, sophisticated hearing protection, and superior audio performance.  It is compatible with most office phones and offers Clearline audio technology to enhance speech clarity.
 
 
Need an amplifier to work with your Poly/HP Headsets check out the JPL Companion