HELP, understanding Speaker Transformers,

[Happy_Jock]

Hi Folks, it seems just as I tell myself I'm becoming more clued up on the workings of electronics and circuits, some small simple project seems to confuse me.

I am trying to create a little project like a push to talk one way intercom type thing with a mic and circuit in one room with an output leading to a speaker in the other room, I assumed this would be a simple project but the most reliable schematic I can find sounding fit for my needs, is this one from Talking Electronics,
[img]http://i1291.photobucket.com/albums/b555/jockthefinch/circ_zps167e1dnz.jpg[/img]

I notice prior to this it explains the speaker needs a transformer and describes the method of creating one
[img]http://i1291.photobucket.com/albums/b555/jockthefinch/trans_zpsdpc51rym.jpg[/img]

Can anybody tell me if there is an easier way around creating the transformer, such as can it be made with a rectangular ferrite stick or a ferrite toroid? Must the gauge of the wire described be exactly that or better still are there component type transformers I am able to salvage from old circuit boards or buy which would be suitable.

Also I am confused on the workings of this type of mic to speaker circuit a lot of examples I see on YouTube have very quiet or poor sound output.

Any help would be much appreciated
cheers