I just love listening to the sounds of birds talking to each other.  Their chirps are just great.
me too! I had parakeets and i loved to hear them talk. Bird songs are the bird sounds that are melodious to the human ear
Bird vocalization
the distincion between songs and calls is based upon compelexity and length, isn't it cool
Are they communicating with each other in any way?
yup. for example songs that are longer and more complex are usually associated with courtship and mating
I wonder how loud some of their songs can get.
songs and which are calls, and a good field guide will differentiate between the two.
Bird song is best developed in the order Passeriformes. Some groups are nearly voiceless, producing only percussive and rhythmic sounds, such as the storks, which clatter their bills. In some manakins (Pipridae), the males have evolved several mechanisms for mechanical sound production, including mechanisms for stridulation not unlike those found in some insects.
Song is usually delivered from prominent perches, although some species may sing when flying. The production
Bird vocalization
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs (relatively complex vocalizations) are distinguished by function from calls (relatively simple vocalizations).
Definition.
The distinction between songs and calls is based upon complexity, length, and context. Songs are longer and more complex and are associated with courtship and mating, while calls tend to serve such functions as alarms or