my opnion it is a nicorette overdose
we all vaped much at the begining since we didnt know what is much with cig when you buy the second cig pack you know you have to slow down..with vape we dont know..ear ringing is much like ear ringing from drining too much beer (not all people ,much blood flow to inner ear) better to vape only 1.5mg and limit your self with 3 to 4 ml a day till you feel ok again.
one thing more i also notice some certain flavours cause me some headache its something personal from one person to another find tour best ejuice.
Just made a purchase of 4 bottles of eliq 500mls total and all are 0mg. I thinks it's time after 10 months quit using either 3 or 0mg. I told myself if I made it to a year, that that's what I had to do.
So if the occasional ear itching and ringing continue, then it's something in the mix. My sinus issues have pretty much disappeared so I can't blame it on that.