One and only; and it was not even related to audio, but hey!
14 years ago (!) I was really digging the “new” Firefox functionality that allowed you to search from the address bar. I was also (and still am) fan of “Sound On Sound” magazine, so I created the OpenSearch XMLs (30 seconds work) and share it on the forum. Martin Walker, saw this and added it as a short note in his article, on October 2005 issue :)