The Internet has an increasing number of specialized search engines,
but this might be one of the most unique. With it, you can search for
various on-line sounds. Common search words like "cat," "dog" and
"baby" returned 200 hits, which would seem to be the maximum it
returns. Conceivably, one could use one of the 113 files found by
searching for "applause" to spice up your lecture.