Weird Nether portal like whoosh sound.

I'm not sure if this is a bug or what. I don't even remember when it started occurring because I usually play with sound quite low. 

I get this wind whoosh similar to when you go in and step out of a portal immediately. Its not the same it sounds like a wind down a tunnel sound. I'm pretty sure its not ambient sound either because It can occur every few minutes and happens 2 -3 consecutively. 

Let me know if this is indeed a bug or if anyone has experienced this.

Thanks in advance.