Something very strange just happened!

So I am at work, sitting at my desk and I get a phone call on my work line. I answer and an Indian sounding woman asks for a person ( I forget the name) and I tell her that she has the wrong number. She politely apologizes and hangs up. Here is the strange part, before she hangs up, there is a really loud ear piercing tone and I went really light headed! I feel fine now but has anyone had this happen before or know what just happened?