Funny you should mention that. Just this weekend at the TMF, I posted some audio clips from tickle sessions I've had. I've tried to share the wealth here, but the Theater doesn't accept mp3 files. However, if your also a member of the TMF, you can download these at
http://www.ticklingforum.com/showthread.php?204395-The-Music-of-Laughter
On the other hand, if you'd like to have tickle stories read to you, and you have a Mac, your in luck. There's a voice feature on there that will read e-mails to you, and I believe the later model Macs also have this for internet websites. You have to highlight the story itself first, or else it will read the entire webpage.
I've copied and pasted tickling stories from here and the TMF onto an e-mail, and then have the voice read them to me. (I've also used this feature in reading the news to me for them longer stories, and just compile the ones I want to hear about in an e-mail format). I've chosen the voice named Vicki, as she has a deep sultry voice with just a hint of a british accent.
I don't think you're going to find pre-recorded tickling stories per se, but with a Mac, you can create your own. Ah to be tucked in bed at night, and have the sultry Vicki read you a bedtime story. Yum.
One note, this won't work with those lazy unimaginative writers who just use a lot of Hahahahahahaha through out their stories, as this just comes off as sounding like a CD skipping. But someone with a flair of descriptive writing skills, yes, it will warm the heart.