Guess the pinout of toy phone schema

[hotter]

Hi, I have this old "toy phone" schema and I would like to play with it a bit and maybe do something useful... But the problem is that schema is without any wires and I am not sure where should I solder 2 speaker wires and 2 power wires. Is it possible to trace it somehow? I was trying but no success...

[kolbep]

I think top left pad will be +3v (the way it snakes through all the switches and then to the IC)
2nd from the right will be the Speaker out (Probably the Transistor is an amp for the speaker?
then maybe the very right hand pad will be 0v for the battery, and for the other leg of the speaker (looks like the only  other pad that had a wire on it before)??

[hotter]

Yes, you are almost right It works when connected like this: to the most left power+ and speaker wire1; to the most right power-; second from right speaker wire2. Thanks.


I wanted to connect it to the Intercom phone ("door phone") and make it ring, but its not that easy, the sound is noisy and quite. I need something else...
Intercom phone schematics:


Maybe someone knows what input is needed for L+ and L-? If someone knows any circuits that would generate ringing sound and work with Line L+ and L- pins that would be great.