Here's a segment of Billy Taylor where you can here him (and almost every time you can see his lips you can see him scatting along) from an incredible series called The Subject is Jazz

https://www.youtube.com/watch?v=UexWRuvJfwQ&t=16m10s

I have an Oscar Peterson CD with audible vocalizations

Erroll Garner

Hiromi Uehara

McCoy Tyner