This just a shot in the dark but try searching for sound effects first. Failing that set your tv to a channel you can't normally get. Record the audio directing from the tv. I'm reasonably confident your baby will not stand up and complain about your recording techniques. Good luck, and hope this helps.

My wife and I were discussing your search for white noise over dinner yesterday. We both find white noise rather grating. If your search for white noise doesn't work we suggest sounds of the sea (an ocean sound) - we thought that might be more soothing as they hear the sound of water for nine months. And if that doesn't work try the sound of a muffled heart beat- they hear that too for nine months.

Happy snoozing !