Have you ever had the experience of turning your phone back on after running out of juice several hours prior, only to be bombarded with a barrage of delayed notifications, beeping and pinging as soon as it connects to the internet? Or maybe you're just in a particularly chatty WhatsApp group and someone decides to send everyone else 20 photos all at once, sending your phone's poor vibration motor into a frenzy? Yeah, that can get annoying.

Fortunately, a change in Android 8.1 aims to address this issue. According to documentation on the new features in the developer preview, apps can now only make a notification alert sound once per second, even if more notifications come in at the same time. The notifications themselves aren't lost, and notification messages will still pop up as they've always done, but alert sounds that exceed this maximum notification rate are not queued and will trigger an alert.

Notifications

Android 8.1 Developer Preview 1 includes the following changes to notifications:

• Apps can now only make a notification alert sound once per second. Alert sounds that exceed this rate aren't queued and are lost. This change doesn't affect other aspects of notification behavior and notification messages still post as expected.

If you've ever used an iOS device, you might have noticed that this is similar to how iOS handles multiple successive notifications from the same app. (I did find the feature somewhat confusing on iOS since there's no user-facing reason why some notifications trigger an alert and others don't, though in retrospect I guess this really was a feature and not a bug.)

Of course, this change would also work as a partial fix for the bug that was causing users to receive a boatload of pending notification sounds when turning off Do Not Disturb, if it had not already been squashed. According to Google software engineer Dianne Hackborn, "the issue with making sounds after turning off DND has been fixed -- that is, it doesn't make any sounds at all," which is altogether a much better solution.

I don't work on this area, and wasn't aware of the limit on making sounds until I saw the public change list. :) That said, from my experience with MR1, I think unrelated to that the issue with making sounds after turning off DND has been fixed -- that is, it doesn't make any sounds at all. (But again, just saying this from my personal experience using MR1, not any actual knowledge of what that team is doing.)

— Dianne Hackborn

Source: Android Developers