Audiologist here.

We treat it like a medical emergency. Reason being if it is a sudden sensorineural loss then they would start you on Prednisone asap. It may help to preserve your hearing.

We think it needs started within a few weeks but earlier is probably better.

That being said, it might not be a sudden sensorineural loss. A hearing test would tell you.

In my experience having seen many actual sudden sensorineural losses over the years, the treatment doesn’t necessarily help in many cases. It’s a last ditch effort really to preserve what we can. Personally, I would probably just wait for morning but I would tell a patient to go immediately.