CULA8R

I also have a 2015 A8 with the Bose and I hear this semi-frequently as well, but what I've noticed is that is almost always immediately precedes a notification or text coming through on my phone. I can't say there a definitive link, but I feel almost certain they are connected.

MP4.2+6.0

I don't think this is true on the device side. Agreed on the bit rate though. Variously, you have the technical limitations of the communication medium itself--like A2DP--and the number of codec's in line with the signal. The latter for example is apparently is a differentiator even as between wired iPod/iPhone and SD card or related transfer to jukebox.

What I can also report is with same album and track on a first generation recording played back to back with a 320kbps (high bit rate) recording with AAC, and with my tired ears, original CD > cabled iPod > bluetooth iPod. The greatest step is from cabled to bluetooth. The step from CD to high bit rate cabled is pretty small. It is less in the D4 than D3 (though that is also B&O relative to Bose), but I can discern it with A:B direct comparisons. I also (painfully) moved my whole library from lower (typically 160kbps) to 320kbps and did note some audible difference and improvement there relative to the original CD's. All of my library is personally transferred from original commercial CD's, so I 100% know the source for all the files--none is downloaded, borrowed or otherwise copied.

Any of them pretty easily better than Sirius BTW, which I have also checked A:B when I hear a familiar tune there and have the same album. With B&O, drop off is quite pronounced.

RedDragonV09

Ive noticed something similar with my 2013 D4, but it chirps 6 times unlike the 3 times mentioned several times already. To me it kind of sounds like a muffled alarm from an old ironman watch. I'll have to see if my dash cam picked it up and if so I will post the clip here to see if its the same noise.

scipaul

I have the same issue in my D4 2017 A8L Sport. 6ish scratchy chirps at random intervals. It isn’t that loud, but very annoying. I just updated MMI to latest and it didn’t fix it. I did not have this issue in my 2015 A8 (or my 2004 A8 &#128514.

2turbos4rings

It was tracked down by someone and found to be a feature that was never launched by Audi. I’m paraphrasing but it was something diagnostic info was sent to the key and this info can be downloaded from the key.

Next time you hear the chirps look at your key and the LED will be flashing in sync with the sound. It’s been removed by some people with a flash at the dealer although most will probably look at you sideways as it’s not common knowledge.

I’m sure all the info you need is in that other thread and should be easy to find with a search and some spare time