Suddenly experiencing massive app lag for cards with audio

In the last ~3 weeks, many cards with audio files are freezing the app for between ~3-10 seconds before finally playing the audio.

I’ve never experienced even a half second of lag with audios before so this is completely new. I have the latest iOS version as of Feb 18

The app is pretty much unusable during this lag, as I have many audio files integrated for language study. There’s no lag for cards without audio, and some audio files are ok, but I haven’t been able to determine why some cards have no lag.

The lag will happen before any instance where the app will play an audio, including tapping the audio button. In many cases, when tapping the “good” to advance to the next card, the app freezes for several seconds before advancing, if the next card has audio.

It also doesn’t get better once the file has played once - clicking the button more times results in a lag each time (and a lag when showing an answer too, if that will cause an audio to automatically play).

Have used the app for years but this is probably a deal-breaker. I completely deleted and reinstalled the app which fixed the issue for a few days but now it’s happening again.

Suggestions? Can the devs fix this bug? Thanks!

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Could you please identify 2 or 3 cards that demonstrate the problem, move them to a different deck, and export that deck, sharing it with me privately so I can try to reproduce the problem?

Do you have a bluetooth audio device connected? Does restarting your phone help?

Generally I am using AirPods Pro to study. I don’t recall if it repros with no Bluetooth device connected but I’ll work on getting a repro and send it over. Thanks for the reply!

I am experiencing the same issue on my iPhone as well… it seems to happen when you try to play the audio file

It seems we are experiencing the same issue, On what device are you using it (I’m with iPhone XS Max) . I also use AirPods Pro to listen to the audio and I tried to delete the app completely as well and it fixed it for about 5 days … What strange is that on my iPad it seems to work flawlessly

I’ve found that the issue occurs when I’m connected to AirPod pro and the auto switch is enabled, but when I disable the auto switch it seems to solve this issue . Also if I without an headphones all together it seems to work perfectly …

Could be Bluetooth audio delay issues, there’s always a lag but depending on distance and ‘electrical noise’ it differs.

Unfortunately I’m not sure there’s much AnkiMobile can do about this - AnkiMobile’s sound handling code has not changed recently, and the bulk of the handling is done by iOS. If the problem has only started recently, and you were using the same AirPods earlier, it’s likely some change an iOS update made.

One way you may or may not be able to work around it is by playing music in the background - that will force the earphones to keep the connection open, and may help with the delays.

It’s not about the delay, but when I play the audio the all app freezes for like 10 seconds… and it happens only with connecting to AirPods via Bluetooth, with the auto switch, once I disable this feature in the Bluetooth settings it solves the issue, I’d like if the dev can check this out cause it’s quite annoying… but it’s not a deal breaker because I found some sort of a solution for this
Thanks anyway

I do think this is an issue AnkiMobile can fix, because I don’t experience such freezing with any other app’s sounds (Spotify, Overcast, 2 Minute Revolution). The app totally freezes severely, in my case usually for 1-4 seconds, but sometimes 5-10 seconds.

Below is a share link of a deck that repros the issue. I have not been able to repro without Bluetooth so that factor does seem connected.

I also seem to be able to work around the issue by disconnecting and connecting BlueTooth. Needing to do that frequently when I use the app is quite inconvenient. Users who haven’t seen this thread (I would definitely thing most users don’t use the forums) will also be confused as to what’s going on and likely put off - AirPods are pretty common and especially convenient when studying on the go, e.g. on the subway.

Using AirPods or AirPods Pro (or perhaps another Bluetooth device) I hope it’s easy to repro.

It’s also mysterious that it seems to consistently repro for some audios every time they play, and not at all for other audios. Perhaps it has to do with the size of the audio.

Lastly, an audio that lags will always freeze the app, but produce different and seemingly random lengths of lag - it’s not consistent.

The difference between the other apps you mention is that they are presumably creating a single audio session that runs for minutes or more. In AnkiMobile’s case, you presumably have audio files that are only a few seconds long. AnkiMobile does not handle the audio playing itself - it just asks iOS to play the file for it, so any delays you are experiencing are most likely iOS or the earphones struggling with the frequent starts and stops. If you have not already done so, please try put some music on in the background with something like Spotify, and see if that makes any difference.

Ok, I can try that out - though for focus I personally wouldn’t use music while studying. Switching Bluetooth on/off when this happens is good enough for now in my case.

There seems to be an underlying, AnkiMobile-specific issue here though. When I use other apps and play various distinct sounds (e.g. MyNoise, Overcast, Voice Record Pro, Google Translate…) the apps never freeze and the sounds start quickly (starting/stopping/switching sounds, whatever).

On the other hand some users have reported apps freezing with airpod use. One solution they mention is to unpair another device (e.g. Apple Watch) and then pair the AirPods first.

In my experience the issue remains Anki-specific but I’ll update if that’s not the case.


Ok, I can try out playing music. Though personally I probably wouldn’t listen during study sessions for focus.

It still seems to me there is perhaps an AnkiMobile-specific issue here since I haven’t repro’d with other apps, including when switching between a number of different sounds. If it’s happening though I’ll try other apps again to see if there’s a difference.

I have seen threads of ppl complaining about apps freezing with AirPods so it very well may not be AnkiMobile-specific though that’s my experience.

E.g. in this case, unpairing an Apple Watch first then pairing AirPods seemed to fix it for people:

I was able to repro this issue and try other apps. MyNoise still did not repro any freezing when starting and stopping various sounds, but Overcast did - starting any already-downloaded podcast would freeze app interaction for several seconds. (Interestingly, the loading spinner would keep going during this time.)

I was again able to work around it by disconnecting and reconnecting Bluetooth.

So that makes me think it’s not an AnkiMobile issue, and could get patched by an iOS update. (I’m on latest as of today, 14.4.) However it does seem like there is some way to get many different sounds to play without a freeze happening, since MyNoise is able to do it.

For me personally this is only reproing every few times I use AirPods Pro with AnkiMobile, and switching Bluetooth off/on is a pretty reasonable workaround. It also seems the fix is not clear from a development standpoint so although it’s annoying this isn’t a huge priority in my workflow.

Did playing music in the background make any difference? If it did, you could play some ambient music or just a recording of silence in the background as a workaround until Apple address the issue.

I haven’t tried that one yet.

Updates here:

  • I can still consistently work around it by disc/reconnect Bluetooth
  • Playing music in the background doesn’t help
  • I have repro’d with a limited number of other apps, not with most. That makes me think there is an implementation difference that avoids the lag. I don’t know technical details of what that would be though.

The fact that background music doesn’t help seems to point to it being a bug in Apple’s audio libraries, rather than an issue with the bluetooth layer. I’m afraid it’s not really practical to rewrite AnkiMobile’s audio code in the hope that it will resolve this issue, so this will probably need to wait for a fix from Apple. :frowning:

I think it is because of the new feature that apple implemented in the iOS 14 ( the auto switch) when you’re using AirPods , if you disable that feature it won’t get freeze any more. try and do it on your settings.

settings→bluetooth→AirPods (tap on the i icon) →connect to this iPhone (change it to when last connected to this iPhone)
it seems to solve the problem for me.

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