So there's this one song that I like called Turn It Up by Chamillionaire featuring Lil Flip. At the beginning of the song (and throughout it), you can hear the familiar "CHIRP!" of a Wheelock NS4! Well its kind of like that only lower pitched or higher pitched i don't know. To hear a sample of the song, follow the link:
and click on "Play" on Chamillitary Radio. It should say the song that is currently playing in a screen above the Play Stop and Forward buttons.