Right, but again are we talking general chatter of a hen or how noisy her egg song is?
Egg song I find can indeed be compared among some breeds, but general chatter noisiness is almost always measured in individual birds, especially hatchery based ones. I find more consistency in non-hatchery stock though.
I really don't have a solid idea on the matter. I know that my cochins never seem to talk but my new hampshire hens chatter all day long. I do have a newbie question though, what is an egg song? This is the first thread I have seen the term on and I'm sorry in advance if I am being rude for asking.
I have found the game breeds I have owned to be noisier in general than the others. They never did much of an egg song, but the hens were talkative, the cocks crow a lot (they walk around the boundaries of their "territory" crowing, I think it's to mark the area as theirs) and any time there was company over, they would crow extra for the next day or two, and they are very alert and anything that catches their attention as a potential threat sets them off into the "alarm" song.
The bantam Cochins I had were quiet hens. The rooster I would say was average, maybe 5-10 crows in a 24 hour period. (He was also at the bottom of the rooster pecking order though, so I'm sure that had an effect)
I had Welsummers for a while and the hens were loud when they were trying to lay. It lasted about 3-4 hours every morning from about 6:30 until 10ish (until they were done laying). My Roos Crowed but not a whole lot. Barred Rocks were very quiet for me. The Roos crowed a few time a day and that all the noise they made. Except for Hawk sightings.
My Silkies and OEGB and Dutch Bantam are VERY talkative. The Silkies complain loudly about anything they are unhappy about....rain, laying an egg, being kicked off a nest etc. My OEGB has a very high shrill chatter that she nakes throughout the day, to say hello, or lay and egg, or complain that she's not let out..... and my Dutch bantam talks to me constantly with a sweet liittle Brrrrp? Brrrrrp? Always a question with her. Usually its "why won't you pick me up? Brrrrp? Why don't you put me in your coat? Brrrrp? Why are you paying attention to anyone other than me? Brrrrp?"