Thank you for providing so much context. A pit bull (short for pit bull terrier) is a dog that is one of a breed that was originally bred for baiting bulls. The "cooing of lovebirds" is a pleasant sound. If the onversation sounded more like "the barking of pit bulls" it wasn't very pleasant. The "lovebirds" would have been showing each other affection. The "pit bulls" would have sounded angry.
Does that help?