There is no 'average' number. It takes what it takes and it varies with each artist.

That being said, vocalists tend to take a bit more time to get something really good than a typical instrumentalist.Even in the case of someone recording stuff they have been playing live a lot.

Things change with the subtlties heard under the phones or on good monitors.

About hitting the record button so many times: I wouldn't worry about that. By the time you need to do it live you have a nice picture of how you want it to be, and you can rehearse until you get to that level live. I feel that the quality of a singer live is very much determined, aside from timing, by his/her ability to strike the first and last note of any phrase correctly. If you miss a few inbetween, only a few will notice. I doesn't hurt to be critical during recording, though. You want to make something that will be worthwile hearing again and again.

If 10 to 15 times includes rehearsals: that's not bad, very good I'd say.

In my case it heavily depends on how much rehearsal or preparation went in before even pushing a record button. I have always wanted to be able to perform a song "live" (not necessarily before live audience) before I start commiting to tape. Lately I have tried to comp a song. i.e. record all the separate verses, bridges, chorus (guitar and vocal) and push and shove 'em around in the arranger window until it makes sense. Then I make myself familiar with the arrangement until I can play it by heart before recording it.

I wonder about others here. I guess there's no rule.

One, no twenty, wait a minute nine, sometimes more sometimes less.
Daves right and so is cfaalm, there is no set number. A tremendous number of recorded vocals are comped. That is individual phrases or words even syllables are pieced together from many takes.
One thing I have noticed is that new original songs are sometimes the most difficult for performers. It seems like when new, these songs don't have the "legs" that other originals that the artist has been performing for a long period do. The really great vocalists often can nail something on the very first take but this is the exception rather than the rule. Some of these people will do three or four takes and I can hardly tell them apart, that is how close they are each time.

I used to be obsessed with getting that "perfect" vocal track (along with that "perfect" track for everything else). Sure, I ended up with a "flawless" take, but I was so tired and frustrated by the time I usually got it that I wondered if it was worth it. The best strategy I've found is to know the piece you are doing 110%, and then let it all loose on the first take. That first take just has energy and spunk that later takes are missing. I have this happen even more with guitar solos. Sometimes I will do about 10 takes, and then I will listen to the first take, and even though it is sometimes quite rough around the edges, it just has that "raw" sound to it. I think what I'm trying to say is to just let it all out and not be obsessed with the details. I mean, it's not like if a live album is being done the band can do it over until it's "perfect." Anyway, just my rambling, take it or leave it... 8)

While I agree that the number of necessary takes can vary greatly, I'm kind of with Dan on this one. In my experiences at least, many musicians/singers tend to flatten out performance-wise when doing multiple takes in studio.
Most of my best takes happen in the first few.

Myself, I would hit the record button even if it's just a rehearsal performance. You never know.
While I haven't tried comping yet, I will on my next project. Not so much w/ the intention of doing multiple takes to comp, but more because of the chance that magic will happen at different points in different takes.

Interesting. I have comped the vocals on a lot of my songs, but it has been getting easier to do takes and get them right (even if it takes a few tries). I really want to make a clip of a song I have recorded 3 times over the past few years, so you can see how much I have improved. It's quite a big difference IMO.

I guess I will start recording just me and the guitar doing a song all the way through to see how it sounds. That's what I really need to practice anyways, but I just love the writing and recording aspect. Nothing really more satisfying to me than hearing a song come together. Not even sex. Well, maybe that.

i agree with everyone. one thing i've learned too is to always be recording, even when warming up, or just doing level tests, run throughs etc.... some of the best takes are often the early ones- before we start to get all uptight about it. and for me, some of the early bits always seem to make it into my final comp.