Great. Thanks tunci, ahmet_a1b2 and AlphaF. A nice group of voice verbs we have here now.

But it is still difficult for me to believe that a cock can sing.

I got an idea. The metaphorical use of animal sounds (with a human subject) gives us a great freedom of expression. (Just don´t forget diye):

                          ...diye homurdandı (I have heard this many times.)

                          ...diye kişnedi

                          ...diye uludu

                          ...

No?

homurdan-mak used for humans and have a spesific meaning.

imagine someone gets angry or heard something he/she doesnt like and saying something to himself/herself, most probably bad things, not always swearing but complaining angrily, but the most important of all, listener cannot understand what he/she says. so from the listener´s point of view he/she definetly "homurdanıyor." actually "homurdanan kişi" doesnt really want the listeners to understand him/her because they dont want to argue with the listener´s, too. But they need to express their unwillingness and anger by "homurdanmak". Also homurdanmak makes the listener a bit angry too. and i think this is on purpose by the "homurdanan kişi" in order to punish him indirectly...

Ayılar homurdanır.....insanlardan anlaşılmaz sesler çıkartanlar ayılara benzetildiği için homurdandıkları söylenir.