Determine if any recent changes have been made to the headset or aircraft.
If any changes or modifications have been made to either the headset or the aircraft, look into whether or not those changes could have unexpectedly caused this issue.
Check if the noise is affected by the volume control on the aircraft panel volume control.
Without adjusting your headset volume, turn up or down the volume control on the aircraft panel. If the noise level changes as well, the noise is related to the signal being received from the panel.
Connect the headset to a different panel jack or, if possible, to another aircraft.
Non-TSO equipment, worn jacks/loose connections, or incorrectly wired jacks (i.e. reversed stereo or mic / ground wires) in the aircraft can cause issues. If available, try connecting the headset to another jack in the aircraft or to jacks in a separate aircraft. If the headset works fine when connected elsewhere, the panel jack or wiring to the jack is the issue.
For 6-pin aircraft-powered installed connections, check the condition of the plug on the headset and the jack on the aircraft.
Check for any debris in the connector on the aircraft and check if any of the six pins are missing inside the headset plug.
Note: If the aircraft has a jack for an older model Bose AHX headset that was wired to provide mono audio to the right earcup, the jack will need to be rewired since the electronics in the newer A20 cable differ.
Determine if the issue occurs when your headset is powered off.
Your headset works in passive mode (powered off with no noise cancellation). If the issue still occurs while the headset is powered off, the issue is related to signal coming being received by the headset from the aircraft panel (i.e. the connections, wiring, or interference).
Determine if the tone of the noise changes when the avionics panel is touched.
If the tone changes when the avionics panel or any other area of the plane is touched, there may be a grounding issue with the aircraft or the intercom connections and associated wiring.
Check for interference that could be causing unwanted noise.
While the noise is present, slowly move or turn your head away from sources of interference — like window heat, antennae, power cords, etc. If the noise is more noticeable as you get closer to a device or area in the aircraft, it is related to interference from that device or area. In some cases, repositioning even just a few inches can help. (Tip: If necessary, the headset can be used in passive mode — powered off with no noise cancellation — to avoid interference).
If your powering your headset from a 5-pin XLR connection on the aircraft, disable the Auto-On feature of your headset.
If an aircraft is powering to your headset from a 5-pin XLR jack providing less that 12 volts, your headset might power on or off unexpectedly or product static. To resolve this:
- Open the battery door on your headset control module
- If installed, remove the batteries to access the headset option switches
- Set the Auto-On switch to the OFF position
- Install or re-insert the batteries so your headset can switch between aircraft and battery power as needed.
Note: When connected to an intercom, your headset still passes all communication while powered off—just without noise cancellation.