My data presently suggest to me that your ear tone was linked at least partly with the following earthquake:

2001/12/03 13:25:08 19.39S 68.98W 104.3 5.3 CHILE-BOLIVIA BORDER REGION (NEIS data)

There appears to me to be something happening in fault zones within 48 hours after an earthquake occurs which can produce an electromagnetic energy field fluctuation which some people who are earthquake sensitive can detect. I do not presently believe that this phenomenon is aftershock related.

The time difference between that earthquake and the ear tone was a little over 6 hours, or 1/4 of a sun - Earth - moon revolution day. That and other data which I have been evaluating indicate to me that the two were probably related.