Huawei
Set a Custom Notification Sound for Calendar Events auf Huawei
By default, EMUI plays one standard tone for every calendar notification. That makes it hard to tell an appointment reminder apart from other alerts just by sound.
The Calendar app has its own notification settings, separate from the system-wide sound settings. Changing the tone there only affects calendar events and does not touch your ringtone or message alerts.
Where the setting lives
Open Calendar ➔ Open the menu ➔ Open the Settings ➔ Tap on Notifications ➔ Tap on Sound ➔ Choose a notification sound.
In the sound picker, you get the pre-installed system tones plus the option to browse your own audio files. Any .mp3 stored on the device shows up as a selectable option, so you can use a custom track instead of a default tone.
If you still do not hear the new sound, check that notifications for the Calendar app are not blocked in the system-wide app notification settings, and that Do Not Disturb or a Focus mode is not muting calendar alerts. Those settings sit outside the Calendar app itself and override the sound you picked here.