When I was in Hanoi and surrounding areas for two weeks almost a year ago, I heard no ear tones. Hanoi is a noisy city, so I don't know if I would hear tones, as we could hear traffic from our hotel room. However, I did travel east to Ha Long Bay and south as far as Nam Dinh, where there is quiet, and I never heard any tones. I wish I had heard a tone or two to see if they linked up with anything seismic. Going two weeks without hearing tones is unusual for me.

Cathryn