Connect the battery - on one module to the battery - on the other module.
Then connect one of the wires on one module to either of the wires on the other, if it doesnt work switch wire son the first module and try both connections on the other.
The idea is you want the grounds -'s to be common, then one of the wires on the clock might trigger the sound module.
Beware this my well not work, and might blow something, but without getting into electronics I cant think of a better way.
If you can get a relay with a 1.5v coil that most likely will work, however I odnt think you'll get one easily.