Can I hear external warning signals when using Active Noise Cancellation (ANC)?

Jabra headsets with Active Noise Cancellation (ANC) provide a linear reduction of background noise, including reduction of noise from warning signals such as a siren or fire alarm. The signal-to-noise ratio between a warning signal and background noise would remain unchanged.

Because the volume levels of warning signals typically exceed background noise significantly, it is expected that the signals would still be clearly audible to a headset user, even when ANC is in use.

Note
In the case that a headset user listens to very loud playback audio such as music, this may impact the audibility of warning signals. This is not specific to a headset with ANC functionality, but is general to all headsets.