Pilot gets a "tinnitus like" ringing when pulling passive G's and descending.

I've noticed that in certain situations, such as aggressively diving or pulling around 3 G's, the pilot of the P-51 will suddenly lose all hearing and will get a strange ringing sound very similar to what people with tinnitus experience. The only way to mitigate this is to keep the oxygen on at all times, which is strange because hearing loss is certainly not a symptom of hypoxia (and it still happens at altitudes below 10,000 ft).

I've confirmed with two people who have over 1,000 hours in fighter jets that hearing is not affected at all while pulling G's until total GLOC, and that the only thing happening to your ears during an aggressive descent is constant popping.

Just spitballing here, but are they maybe trying to model the effect of pressure changes on your ears? Does it only happen during vertical maneuvers, or does it happen in flat turns as well?

Edit: Just wanted to add a little more detail in relation to fighter jets versus the P-51. Most fighter jets these days have pressurized cockpits. The P-51 doesn't. If I'm able to coordinate with a customer of mine who's P-51D I take care of the avionics on, I'll ask him about the ringing in the ears during hard maneuvering and dives. He has a few thousand hours in the P-51D and flies 2 or 3 times a week lately, more often during race season.

Eagle, I fly aerobatic aircraft (with unpressurized cockpits) a few times a year and while not as high performing as the Mustang, I have never noticed a loss of hearing or tinnitus while pulling hard G's. It seems like a glitch to me ...

This has me curious now. I have 2.5.5 and 2.5.6, so I'll give it a try in both and see if maybe it sounds like something else I might be familiar with from various aircraft I've flown in. The only unusual sounds I dealt with lately in my customer's Mustang were coming from a wonky PTT switch. :D

Confirmed in 2.5.6 on my rig too, with the Reverb. Its not due to climbing, diving, or pulling Gs though. I'm finding a repeatable result at about 410 knots, and the loss of hearing doesn't go away until your speed decreases to about 380. Definitely doesn't seem right. Almost like its giving similar effects on sound as what you get in a DCS jet when approaching mach. Weird. I'll try the same conditions in 2.5.5 and see if I get the same thing. Might also have to try the A-10C and see if it does the same thing in a dive when it finally hits 410.

I'm on the Free Flight Over Poti instant action mission, and at 6200 feet I roll inverted to start a dive, and ride it down. As soon as I hit 410 knots, I get ear ringing, followed by severely attenuated cockpit sounds. The ear ringing sounds pretty much exactly like I just fired a rifle with no ear protection. Sharp, but fades quickly.

No issues in 2.5.5. Went back to 2.5.6, had the same issue in the P-51D. Tried the A-10C at 410 knots in a dive and had no issues. The really weird thing is that the TF-51D doesn't have the issue either in 2.5.6, just the P-51D.

Thank you Eagle for investigating that. I am sure one of the WW2 developers or senior admins will see your work and note it!

:thumbup:

Someone in another thread said to set the Oxygen to 100% and it would go away - something about a bug in the current version.

Yeah, it's really bad. Also it comes on at zero G, which isn't stressful to the body at all. I've also had it stick on and, while the ringing went away, the aircraft sound never returns.

The physiological G effects in DCS need an across the board review. It's ridiculously sensitive right now, particularly in the negative G regime. -1 G (the same as you'd experience hanging upside down while stationary) is enough to induce redout then blackout. Have you ever crashed, gone inverted, then had your pilot black out merely from hanging inverted from his straps? It should take hours before anything that bad happens, not seconds. Same with flying inverted. Sure, if you push several negative Gs severe effects come on quickly. But -1 shouldn't be nearly enough.

Confirmed that setting oxygen concentration to 100% makes it go away. Also confirmed that with oxygen set to normal, ringing also shows up when in a gentle climb and airspeed falls to 170 knots. Definitely not random, it is reproducible, but the conditions that cause it make no sense at all.

So playing around with this, shutting OFF the oxygen supply also makes the ringing go away. I've also noticed that when the ringing is happening the G effects like black out don't appear normally when they should. Setting oxygen to 100% or emergency off makes the ringing go away and G effects such as black out will happen normally again.

Still experiencing this in 2.5.6.47224

Here is a track file in which it occours as others have described.

White Noise.trk