Rephrased an ambiguous sentence in docs/topics/signals.txt.

docs/topics/signals.txt

@@ -47,8 +47,9 @@ You can also `define and send your own custom signals`_; see below.
 Listening to signals
 ====================
 
-To receive a signal, you need to register a *receiver* function that gets
-called when the signal is sent by using the :meth:`Signal.connect` method:
+To receive a signal, register a *receiver* function using the
+:meth:`Signal.connect` method. The receiver function is called when the signal
+is sent.
 
 .. method:: Signal.connect(receiver, sender=None, weak=True, dispatch_uid=None)