The volume on mine is horrible, its barand new but even with volume on high its very faint to hear the person.

replace audio

This type of audio feedback loop can happen on any mic if you are playing back audio at a loud volume on speakers that are close to the mic while the mic is on - which tends to happen on Skype calls. Try lowering your speaker volume or using headphones to hear the audio, then speak into mic, and the feedback should be reduced.

its because your sound system is too high for your speakers i thnik

Other than setting the volume controls in the software, make sure you plugged the speakers into the proper jack. Sometimes there are several output jacks, there may be a line out as well as an amplified out. If the speakers are not amplified, and there is an amplified out jack, try that one.

Check for ground loops.

You MIGHT be able to cut the noise by setting the EQ's to clip the highs.

ur speaker phone is not working fine try to replace it or check it with your voice recording so it will confirm that u need to replace it or not

when anyone ring us, we can't hear them they are faint . they can hear us fine. is there a function on the phone or machine were i can turn the volume up to hear them ???

having volume problem, can't hear ring tone
is there anyway to increase volume?

You may have the tape monitor button pushed in or if you look on the back of the unit you may find a pre-out/main-in set of rca jacks. If you don't have a switch to bypass those jacks then you will need to use a set of 2 RCA jumper cables or some stubs made for that purpose. Hope this helps.

Here is the link for the user manual if you need it; http://service.us.panasonic.com/OPERMANPDF/KXTG5621S.PDF page 12 gives battery replacement instructions. I would expect a new battery would solve the problem, even if the charge indicator says that the battery is fine. Something to also check is that some dust or whatever hasen't got lodged in the headphone socket on the handset - that could have this effect. check the voice enhancer settings - page 31 - try changing them and see what you get. Hope this helps - my bet is on the battery :)