Is the audio beeping loud enough to be heard over a headset in the cockpit?

Yes. Both XRX and MRX incorporate an internal audible tone generator (3.2 KHz) which beeps to advise the pilot and passengers of a traffic alert or advisory. This tone is high-pitched and at a volume that can be heard over the noise level in a standard cockpit, similar to the stall warning horn or the outer marker tone. Because noise-cancelling headsets generally reduce noise at a much lower frequency (approximately 400 Hz and below), they have little effect on restricting the volume of the tone generator, which can be heard clearly through ANR headsets. The tone is a short double beat for advisories, or a triple-beat for alerts. The tone is only heard once when the advisory or alert is first announced.