Two people can't talk on the three cordless phones at once

Either you need a new cord that goes from the wall to the base or the phone's electronics parts are going bad. You can try a new cord and if that does not help, buy a new cordless phone because it is not worth repairing it.

Go to Settings > SOUND > Silent mode (No sounds except media and alarms).
If this is ticked (on), it means umts smartphone alarm will sound even if you make the phone silent.
Regarding the loud sound even after reducing ringer volume, no idea for this.

Not unless the phone as 2 lines but u have to call the both people or the person you called can but it go's both ways you just have to press the talk button then call someone then press talk again then call that person then press talk again and you all three should be on the same line

It is possible. You gotcha try it out by carrying your cordless to neighbors hose and see if u can connect from there. If so get panasonic to change the frequency of your cordless........................sodeep

Your phone has Digital Enhanced Cordless Telecommunications (DECT), known as Digital European Cordless Telephone[1] until 1995, The digital filters will prevent interference from the bandwidths used by phones and wi-fi.
Your phone also incorporates dynamic channel allocation which switches frequencies when noise(static) is encountered.
Eventually your conversations take a wire route down the road. You are getting some "cross talk", an actual scientific term used to describe signal transmission from one line parallel to another by magnetic eddy currents. I would call the phone company and have them trace the problem.

most units can only "talk" with one unit at a time, because they are using a set freq. for both sides of the conversation. (think walkie-talkies of children) you can't talk and hear at the same time!

tell your daughter not to talk about her friends that way ;)

A walkie talky as we called them, back when we were younger - and hell we probably still do in some respects, hence the fact my friend still refers to her cordless phone as a "walkie talky" and the principals haven't changed that much.

The common old Walkie Talky or CB radio use what we call a half duplex, that means only one person can talk at a time. We are talking and listening on the same channel.

Cell phones are full duplex, meaning two way conversation, and this is simply listening on one channel whilst talking on another, so the basic principal is basically the same, just a little more sophisticated.

Walkie-talkie typically has one channel
CB radio has 40 channels.
Cell phone can communicate on 1,664 channels or more!

I have included a link to a circuit diagram.

http://www.freeinfosociety.com/electronics/schemview.php?id=1870

There is also two links below, building the transmitter & receiver.
Transmitter: http://www.zen22142.zen.co.uk/Circuits/rf/2bjttx.htm
Receiver: http://www.electronics-tutorials.com/receivers/regen-radio-receiver.htm

Trust this helps, and please take the time to rate the answer given, thank you.

If you mean you want to have someone on each of your extensions listening to the same conversation, it can not happen. The reason for this is the first phone to pick up makes a connection with the base. The other phone will not be able to make that same connection as long as the first one is still on.

Here are some steps that should help. I don't think that you can Conference call You can hold a 3-way conversation (conference call) between your handset, an external caller and another internal handset user. During an external call: 1 Press . The external caller is put ?on-hold?. 2 Press or to select name, number or the handset you want to have a conference call with and press or key. The called handset will ring. 3 When the called handset answers, press to start your conference call. 4 Any handset can press at any time to leave the conference call. It looks like you can use the multiple system sets together, but the system is not designed to do what you are asking for. Please repost with any other comments or questions. Please rate this solution through fix-it. Thank you.