Knocking down internal walls

Hello
We are thinking of knocking a couple of walls around the house. One divides the kitchen to the dining room and we know it isn't load bearing as a few of the neighbours have done it already, but the other is a wall with an archway through to the sitting room and we are not sure. It sounds hollow for most part but from about 30cm from the corner the sound changes. Is this an indication of a support wall? The idea is to fit pocket double doors in this to close up the sitting room so we wouldn't need to knock the wall entirely. Will partially knocking a support wall have an affect? Are we mad to even consider it?
Thanks

You really need professional advice.
I would doubt if many people would be prepared to advise you, sight unseen, on what could potentially be a very expensive mistake.

We woudn't do the work ourselves, just wanted to know the options we have before ordering the frames for the doors. I imagine if that wall is a load bearing one it will be costly to do and will probably just build a fake wall against it instead. I thought that if only about 30 cm of a wall is solid and the rest is hollow it may give an indication of the type of wall it is, is there anything obvious that we could look for to determine if the wall is load bearing or not?
Thanks

Have a look at the floors upstairs to see which way the joists are running. If they run parallel to the wall then it is unlikely to be load bearing.

Seek further advice from a professional, depending on whether it is or isn't load bearing.

Not mad at all..

Its done all the time...engineering term for this is to install a picture frame to take all loads down the same path to foundation level.

Partially agree with the checking the floor joists. However the roof structure may also be resting on this wall. You may also find that an RSJ may be picking up the joists with the RSJ resting on the wall to be removed.

Long story short...You are better off getting professional advice on this issue....an Engineer

Thanks for the advise. Will call the professionals.