AirPods Firmware 9A348 — Possible Left/Right Audio Imbalance Bug

Question

Level 1

17 points

AirPods Firmware 9A348 — Possible Left/Right Audio Imbalance Bug

I have an AirPods 4 with Active Noise Cancellation, and I've been using them normally for over a year. Over the past two days, I suddenly noticed that the sound in the left ear became muffled, which was also causing an uncomfortable feeling in my ear.

I followed Apple's recommended troubleshooting steps, including resetting the AirPods, but the issue persisted. There is also no visible physical blockage or debris on the earbuds.

Today, after testing for quite a while, I noticed some very specific behavior:

If I put the right AirPod in first and then put the left one in, the left ear will sound muffled.
However, if I switch the listening mode once (for example, from Off → Transparency → Off), the muffled sound immediately disappears.
If I take the right AirPod out and put it back in, the muffled sound in the left ear also disappears.
If I put the left AirPod in first and then the right one, the problem does not occur.

So the issue seems to depend on the order in which the two AirPods are put in, and it can be temporarily fixed simply by changing the listening mode or reinserting the right AirPod.

My AirPods are currently running firmware 9A348. I checked Apple's official firmware information and found that 9A348 is the latest firmware version that was recently released.

I also searched for “9A348” on Xiaohongshu (Little Red Book), and found that I'm apparently not the only person experiencing this kind of left/right audio inconsistency.

I also posted about this issue on other social media platforms. Several people have already commented that they are experiencing a very similar, or even exactly the same, bug, including the left/right audio becoming inconsistent and the issue disappearing after switching listening modes or reinserting one of the AirPods.

Because the problem is highly reproducible, appears to depend on the order in which the AirPods are inserted, and can be immediately resolved by switching modes or reconnecting/reinserting an AirPod, I suspect this may be a firmware/software issue introduced with 9A348 rather than a hardware failure.

Has anyone else experienced the same issue with firmware 9A348?

Posted on Sep 17, 2026 8:55 AM

Reply

Answer 1

WheelieNick

Level 9

69,640 points

Sep 18, 2026 1:09 AM in response to QiaPo

Hi there

please try this

Force a Clean Reset: While it won't downgrade your firmware, performing a hard factory reset can sometimes clean up corrupted initialization cache. Put both AirPods in the case, hold the setup button on the back for 15 seconds until the status light flashes amber then white, and re-pair them.

Toggle "Headphone Accommodations": Some users on social media noted that turning off Headphone Accommodations (found in Settings > Accessibility > Audio & Visual) reduced initialization anomalies when AirPods connect.

Reply

Answer 2

OldToad

Level 4

1,043 points

Oct 9, 2026 3:55 PM in response to Justerlone

You might try resetting both your AirPods and iPhone a couple of times in a row according to the following:

How to reset your AirPods and AirPods Pro

Force restart iPhone

Reply

Answer 3

Oct 9, 2026 5:15 AM in response to QiaPo

Has anyone solved this problem or does anyone know how to fix it? I even contacted Apple Support, but right now there’s nothing they can do other than wait for a new firmware update—and there’s no telling when that will arrive. I’m still having pairing issues, and every time, I have to take the earbuds out of my ears one by one before they work properly with the right volume and bass.

Reply