We've had a string of headset misfortunes.

First, my Lightspeeds started acting up (some sort of ANR problem - more of
an annoyance than anything), so they went back to Lightspeed for a fix.
When they came back, the ANR was working, but the headset volume was so low
the headsets were not usable. In a conversation with Lightspeed, it turns
out that they upgraded my headsets when they were at the shop and the
upgrade (a new battery box with a cell phone adaptor) has a problem with
some intercom installations and gives the symptoms I'm experiencing. So
Lightspeed is sending me a "new" old-style battery box as a replacement.

In the meantime, I was gonna use Kelly's Telex headsets, but those babies
are deader than heck. The little power light on the battery box won't even
power up and the ANR doesn't work at all. So they are headed off to visit
the Telex service center. Their guess is that the circuit board in the
battery box has gone belly up.

So, I'm stuck using the 'ol reliable $89 David Clark knock-off's I got when
I earned my license. They are not nearly as bad as I remembered, and it is
nice not having to deal with a battery box and AA batteries that die at
inconvenient times...