Barking still continuous but a bit slower and lower pitch: The lowering of the pitch and the
slowing of the rate suggests that the dog is sensing an imminent problem. Thus, this sound means,
“The intruder [or danger] is very close. I don’t think he’s friendly. Get ready to defend yourself!”
Barks have extended their meaning well beyond their original alarm call function. By adding
certain sound nuances, they have become ritualized signals that convey some more subtle meanings.
For instance: