I've noticed that almost every time I attempt a WILD, this same thing happens to me. Probably about 10 minutes into my WILD once my body is relaxed, I start to get this ringing in my ears. I found a thread from quite a few years ago with someone who very accurately described the ringing sound that I get:

Quote Originally Posted by lemmefly View Post
For me it usually begins with a low volume rushing sound, but often I can turn it louder just by concentrating on it. After a wile the sound turns into something that is more like ringing, I would describe it as a vibrating sound wave. I then just let this get louder and more intense until I can feel my body vibrating and hear this really loud ringing.
Afterwards I just wait until it stops again and just stand up with my non-physical body in a copy of my bedroom.

The vibrations and sound are basically trigger and indicator at the same time. After the vibrations fade off, you might think that you are still just laying there with your physical body and actually miss the opportunity of just entering the LD. I had that happen to me a couple of times before I realized that I was in an LD already and didnt have to wait for anything else after that.

My success rate with this is pretty low though, I can do this maybe once every 2 weeks and usually only with WBTB.

Hope that helps.
I have never had a successful WILD, however I do feel like I have gotten close. Usually I can't get past the ringing sound, but a couple times I have started to feel the vibrations at the peak of the ringing noise. So my question is, does anyone else get this ringing sound while attempting to WILD, and has it led to a successful WILD? Thanks!