Bose A20 Interference in 737
 

I recently bought a Bose A20 headset and I've been using it in the 737. I really like the headset, it's comfortable, clear, and has good ANR.

The only problem is the ANR seems to have some kind of interference with the electrical system on the 737. I've tried two different headsets and both have the same issue.

Once the generators are brought online, and for the rest of the flight, I can hear a high frequency thrumming noise (I don't really know how better to describe it). The noise gets quieter if I turn my head sideways in the cockpit. Also, the noise is there even if the headsets are not plugged into the aircraft, but the ANR is on.

It's not that noticeable on the 900s, but on the older 800s it's really noticeable and very fatiguing on a 4-5 hour flight (have not been on a 700 with them yet). I've called Bose several times about it, and to their credit they sent me a replacement headset really quickly. Honestly I don't think it's a problem with the particular headsets but the Bose not playing well with the 737.

Has anyone else had these problems?

I’m pretty sure it’s the window heat

had the same problem using the A20 and the U Fly at 2 companies on the 737. I think it's the Boeing window heat but so far the clarity aloft has treated me really well. YMMV depending on intercom/rubber band usage.

For the most part, mine works great. The only exception are a few of the 800s that create a slight oscillating hum (I can’t describe it either). To be honest I thought it was ambient noise causing an issue with ANR.

Since I have only a few issues, try this. I’ll get you a picture in a couple of days. I wedge the ANR battery pack between the visor track and the plastic just above the R2 window and directly below the jacks for the headset. I use the clips on either side of the battery pack to hang itself from the far side (away from you) of the visor track. I point the control panel up, which keeps the blinking light from bothering the OCD captains on night flights. Sorry but it’s difficult to describe.

I only have the issue with 1 out of 20 800s, so maybe placement is key.

Sometimes replugging or moving the plugs in the jacks helps.

If you have cabin interphone audio selected on most airframes it causes a hum. And on some its really loud.

Ahh thanks. I was also considering the UFly, but maybe not if it has the same problem. Has anyone noticed ANR interference with the David Clark ANR headsets?

Oscillating hum is a good way to describe it. I will try your method on my next trip. So basically you are keeping the battery pack as far away from the window heat as possible? Thanks for the tip.

I have definitely heard this hum. It's a more constant hum and different from the one that seems to be caused by the ANR. Luckily I can just turn the cabin off when not needed.

Glad you brought this up, I didn’t think it was electrical interference. I’ll get you a pic in 2 days.

Thanks for bringing this up..I didn’t think it was interference... I’ll get you a pic in 2 days.

Weird Noise
 

If the sound is a "reverberating" noise that has a physical vibration-type feeling against one or both ears, then you should also check the size adjustment on your head. I am told by the folks at Lightspeed, that if you have it compressed too tightly against your head this phenomena can occur with any ANR headset.

It doesn't seem to be a physical vibration. I have tried lots of different adjustments and it never seemed to help at all unfortunately. I'll try again on my next trip just to make sure though. Thanks.