Android will alert you if you’ve been listening to audio at a volume above the recommended level for long periods over your headphones. You can keep listening or lower the volume. This was announced during the “What’s new in Android Accessibility” session.
We’ve actually been tracking this feature since before Google announced it and have a few more details to share.
Android keeps track of how often you’re “exposed” to excessively loud “sound doses.” The OS can show warnings about “momentary exposures”, but once you exceed 5x the “loud sound signals” you can “safely listen to in a week over headphones”, Android can auto lower the volume.
This feature is controlled by config_audio_csd_enabled_default, which is now enabled by default in Android 14 Beta 2. It seems this “headphone loud sound alert” feature is intended to comply with updated recommendations in the IEC 62368-1 3rd edition.
We couldn’t get my hands on a copy of this document to tell you exactly how this works. You have to pay ~$452 for it, and all We want to see is chapter 10.6.5 – protection of Persons.
We did find a document summarizing the requirement, though. “In 2018, IEC 62368-1 was reviewed and the concept that weekly sound dose should be limited to the equivalent of 80dBA for 80 hours/week or 1.6 Pa²h as a standard safety level was also added to this standard.“
If I’m not mistaken, the volume safety recommendation in the previous edition of IEC 62368-1 is what formed the basis of Android’s existing warning when you try to raise the volume of audio (when connected to a headphone) above a “safe level”, as required IIRC in the EU.
Parts of this feature are already implemented in AOSP (eg. the HAL), though I’m not sure if the feature is actually functional in Beta 2 yet. Once Android 14’s source code is out, we can see exactly how it works.
