> An audiologist friend told me to go to an ENT physician if not better by 48 hours or the damage could be permanent. Much longer than that and it would be too late to try any of the interventions
This seems like poor advice. If there is significant, realistic concern about permanent damage, I'd suggest checking immediately, rather than give it extra time...
This seems like poor advice. If there is significant, realistic concern about permanent damage, I'd suggest checking immediately, rather than give it extra time...