APNS notifications - too quiet custom sound

Our application is designated to be used in a quite noisy environment (childcare facility) so we have implemented really annoying custom sounds. Unfortunately the system audio session playing custom sounds is apparently limited to half of the device volume possibility, even though the user sets full volume in the settings. How to change this behaviour to get louder notification sounds?

To be clear, I don't want to overcome user settings. If the user sets quieter volume or he sets the silent mode, the application should be silent too. I just need that 100% volume settings is actually 100% device volume.

This is a really critical feature for us and for our customers. We have already tried to ask for the critical alerts and we have been rejected.

Notification (and ringer) volume is an additional setting on top of the device volume in Settings.

Settings -> Sound & Haptics -> Ringtone and Alerts slider will control the volume of the ringtone and various alert sounds including notifications, in addition to the device volume setting.

If you have maxed that setting and the volume is not still satisfactory, and you have also maxed out your sound design, you may want to file a feature request or bug report at https://feedbackassistant.apple.com/

Bug Reporting: How and Why? has tips on creating a successful bug report.

Thank you for your quick response.

Unfortunately, it doesn't solve the problem as the volume settings, you are talking about, is the exact one I mentioned in my previous post.

The fact, that notification sounds are much quieter than "normal" sounds, is observed consistently by us on iPads and iPhones, and according to this forum thread https://developer.apple.com/forums/thread/800487 it seems that it's quite well known to Apple engineers too.

So, is there any solution how to make notifications (alerts) louder?

APNS notifications - too quiet custom sound
 
 
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