Wow, funny you mention this. Have used my QC and Mr Fish his QC2 on many 767 flts, never had a problem until Monday. Mine started half-way thru the flt (when the reel re-started), and I figured my headphones were on their way out. Then, Mr Fish's started a little while later. Not really a pinging with ours, more of a hum/deadening sound coming and going. Since both were acting up, I figured it must have something to do with the plane equip rather than the headsets, it just never happened before.

Robin