Unable To Find A Trigger. I Have A Whooshing Sound

Unable to find a trigger. I have a whooshing sound (sounds like two Bart trains passing one another). It is pulsating and happens only in the am, when I get out of bed. It can last several hours. It goes away when I sit but will resume when I start walking. It almost pulsates with my steps. I am scheduled for surgery on Friday and had this happen last week. There is no regularity to the whooshing. It just happens about once or twice a month. I feel very off, when this happens, not normal.

Thank you.

YYYY@YYYY