Why do some cats purr a lot, and some don't?

[Fat Freddy]

Most of our cats are just regular purrers, but we have a couple with really loud purrs that sounds like a motorboat, and a couple with a quiet purr.

The "silent purrers" purr like everybody else, but you can't hear it unless you put your ear right up against them.
You can also feel their purr with your hand when you pet them.

Sometime we will have three four cats sleeping with us at night and we fall asleep to a Purr Symphony.

[Arope2248]

my cat meona purrs all the time it kinda is annoying well all of everyones replys really helped peace (>")>

[bjh]

Some cats purr very quietly. Others more loudly. One of our current cats, you wouldn't think she ever purrs if you didn't gently touch her throat and feel the vibration of her purr.

We were joking just the other night that if we put kitty to our ear maybe we can hear the ocean. Maybe you had to be there.

[Macrina]

My Carly didn't purr for the longest time...not for Years. But in her old age, she sometimes will now purr...and it's not very loud, but it happens.

One time, though, she started purring loudly, and it was as though she couldn't stop: she even drooled a bit, and I had to wipe it up. Then I began laughing a little and she gave me this look, and jumped down from my lap, in high dungeon. That made me laugh harder, (don't even think she didn't know she was being laughed at...) and and so she did her absolutely Worst & Mad behaviour: she turned her back on me and sat on the carpet right in front me in her 'hunching' mode!

She thinks this is doing just something terrible, I guess. Anyway, it's her most vengeful behaviour. (Isn't she a sweet softy?)

[SookieStackhouse]

Mine purrs a lot, and always has.

[tcrackly]

My dear departed kitty was a foundling. She didn't purr for years. Then after 7 years or so (this was after we got a dog, too) we always got a giggle when she would purr loudly. I guess it took her time to get to her comfort zone.