strange tapping sound

I keep hearing a strange tapping sound from my laptop computer. It is just like the old windows assistant noise in XP when that annoying paperclip man would show up. It sounds like a paperclip tapping on glass. It seems to occur randomly or at least I haven't identified any connecting factor. It even occurs when I'm not actively using the computer. This tapping noise isn't in my windows sound scheme. What worries me most is that the computer may have identified someting I should be dealing with. Has anyone else come across this? What is causing it?

Thanks for your response Brummyfan. My concern isn't so much the noise but that I don't know what is launching it. Sounds usually accompany an event or action and since it isn't something that I'm doing then why is it happening?

The sound is from the speakers. Do you remember the paperclip man in WinXP?

Are you positive that it is a sound coming from the speakers? I had an issue with a hard drive making a tapping sort of sound intermittently. If you have a replacement available give it a try-this solution worked for me.