We've heard of three scenarios:

1. You do not hear any audio
2. While studying, you are missing audio for a few words at random
3. While studying, your audio starts off fine, but then stops working
4. For some words, audio seems to never work

1. You do not hear any audio

• First, check other programs on your computer or mobile device to make sure your sound is working, enabled, and not muted. If you're using headphones, make sure they are connected properly and are able to produce sound in other environments that you are sure should work.

• Head to our dictionary entry for Beijing: 北京 and click the 'play' buttons for the word and the sentences. If you *cannot* hear any audio there, head to NCIKU and see if you can hear audio there.

• All of our audio files are stored on Amazon S3 (a set of super-fast servers built for speed and stability). If you can hear audio from your device (including other websites) but not our audio, try turning a VPN on while using Hack Chinese. 

2. While studying, you are missing audio for a few words at random

• During a study session, we can load up to 600 audio files. For example, in a 20 minute study session, we load 300 words, along with an audio file for each word and it's associated example sentence.
• On desktops, this is usually fine. But on mobile devices, we have heard that a few audio files may not load correctly. If this happens, you can try to 'replay' the audio (by pressing word itself or example sentence), which should trigger a re-load, but this is not guaranteed to work.
• We do not load all 600 at once (as that would be too demanding on your internet connection, especially on mobile devices) -- but rather we pre-load a few words' worth of audio shortly before you need them.
• This tradeoff means that if your Internet connection is not stable at the moment you are downloading audio, the download will fail. If your web browser attempts to download audio and fails, it will not try again unless you ask it to (by manually triggering a re-load).
• If you are able to use a desktop, you will most likely not encounter this problem.

3. While studying, your audio starts off fine, but then stops working

• In July of 2021, Chromium (the browser engine that powers several popular browsers) introduced a cap to the number of audio files that can be loaded and active in a window at one time. (This change caused several mainstream websites to break, and there was a lot of blowback from the development community!)
• Our workaround is to destroy audio elements from the study session once we do not need them. Combined with loading only a handful of audio files at a time, we are able to stay below the limit, and should not see any issues.
• If you are still encountering this issue, please let us know what browser you are using, how long your study sessions are, and whether you are using a mobile device or desktop computer.
• The best way to work around this for now is to use a desktop and/or shorter study sessions. Desktop browsers have higher limits for the number of audio files that can be active in a single window.
• In the long-term, these issues will be resolved when we go to native iOS and Android apps.

4. For some words, audio seems to never work

• For an extremely small set of words (significantly less than 1%), we do not yet have audio. These are typically words that were added by users with our approval queue system. We are working on a way to dynamically create audio for new words as soon as they are approved by our admins.