Noise on Yahoo PC-PC calls

Hi all, Hoping someone recognises this problem and can give me a few hints as I haven't been able to fix it with my own research or any info from Yahoo. During PC-PC calls on Yahoo Messenger with Voice I am getting background noise. Sometimes it is bearable other times not. It sounds like a data stream - rather like short wave data transmission if anyone has heard that, or a softer continuous version of a dial-up modem handshake. (Curiously I am also getting a ticking sound that coincides with the timing clock in Yahoo though I dont think this is a feature). The person on the other end though gets a mostly clear and good quality signal. I am not running anyother internet based programs during the call. At this time I am suspecting my connection speed (see below), but really can't afford to upgrade my plan unless I am sure it will solve the problem. I have yet to try another service such as Skype. I am running.. MS XP Sp2 Yahoo Messenger 7 USB headset/mic Netgear Ethernet ADSL modem Single PC no network 1Gb RAM Test results are.......... Speed test statistics --------------------- Download speed: 219552 bps Upload speed: 56136 bps Quality of service: 99 % Download test type: socket Upload test type: socket Maximum download pause: 145 ms Average download pause: 53 ms Minimum round trip time to server: 378 ms Average round trip time to server: 443 ms VoIP test statistics -------------------- Jitter: you --> server: 8.3 ms Jitter: server --> you: off Packet loss: you --> server: 0.0 % Packet loss: server --> you: off Packet discards: 0.0 % Packets out of order: 0.0 % Number of supported VoIP lines: 0 Estimated MOS score: 2.8 Thanks in advance regards Loz ps sorry for the long post.