I have found this product very dissappointing! BUT... Because I am a tecky of sorts I am not sure that it may/not be an issue of compatibility with my existing telephone headset. My current headset is not plantronics and I am yet unclear whether that factors in. However the amplifier will cut off quickly if there is no sound transmitting through the mic/mouthpiece. and render the headset mic muted. As in a long winded conversation where you are listening to your caller. I have found this very disturbing. I have to watch to see if the light goes off on the amp. because I know the mic has muted and I mustdisconnect/separate the amp from the headset in order to clear my mic.What you can do is put me in contact with the technical division of the Manufacturer of this product. I have some hearing challenge and I am in need of a product such as this. Also note I have found the headset amplifiers on other headsets limited in their ability to make the sound loud enough for me. I purchased this product with both excitement and anticipation. Please advise. Thank you for this opportunity and may I expect to hear from you at your very earliest convenience. Barbara