Boosting "sidetone" on an office telephone headset

Does anyone out there know of a telephone headset that allows you to control the volume of the other caller, as well as the volume of your own voice that is transmitted back to the headset? AKA Sidetone.

I spend lots of time on the phone talking with customers I have never and will never meet face to face, so my voice is the first and last impression. I want to do a better job of controlling the pitch, tone, & inflections of my own voice. That's hard to do when I can't hear exactly how my voice sounds to the person on the other end.

I searched all over the place and found discussions of sidetone, but no technology that addresses the independent control of volume of your own voice.

Thanks

 

Yes Lamour, I am working on a phone sex hotline.