After spending a lot of money for a wireless replacement to my older wired office Plantronics S10A headset, I was sorely disappointed. The sound quality on both the transmit and receive is tinny and distorted. A buzzing sound accompanies the voice in the earpiece, and each person I spoke with complained that I must be using a cell phone with a bad connection. I spent two days trying all the many adjustments for different sound levels on both speaking and listening, but nothing got rid of the buzzing, hissing, and distortion. I went back to my old wired S10A, and was rewarded with a HUGE improvement in sound quality - a reasonable tradeoff for living with the wire. I sent the CS50 back for a refund!