Why can’t I change the notification sound?

The two-tier sound system on macOS

Notification sounds on macOS work in two layers:

1. System alert sound — The default sound used by most apps. You can change it in System Settings → Sound → Alert sound, but the change applies globally.
2. App-specific sounds — Some apps (Slack, Teams, Discord) ignore the system alert and use their own built-in sounds. Whether you can customize those depends entirely on the app.

If you change the system alert sound and an app still plays its own sound, it’s because that app is in the second category — it controls its own audio.

Which apps let you change their notification sound?

It varies widely:

• Slack (Mac): Lets you change the notification sound in Preferences → Notifications. You get a handful of built-in options, but you can’t use your own custom sounds or set different sounds per channel.
• Microsoft Teams (Mac): Does not support custom notification sounds on macOS. The custom sound feature is only available on Windows and the web app. On Mac, all Teams notifications use the same built-in sound.
• Apple Mail, Messages, Reminders: These use the system alert sound. You can change the global alert, but not per-app.

The Teams limitation on Mac

This is a common source of frustration. Microsoft’s documentation confirms that custom notification sounds in Teams are available on Windows desktop and the web client, but not on macOS. On Mac, there is no setting to change the Teams notification sound. If you’ve been looking for it, you’re not missing something — it simply doesn’t exist.

Troubleshooting: no notification sounds at all

If you’re not hearing any notification sounds, check these settings:

1. System Settings → Notifications → [App] — Make sure “Play sound for notification” is enabled.
2. System Settings → Sound — Check that Alert volume is not set to zero.
3. Focus mode — If a Focus mode is active, it may be silencing notifications. Check System Settings → Focus.
4. App-level settings — Some apps have their own mute or Do Not Disturb toggle (Slack, Teams both do).

How Chirpy gives you control back

Chirpy works at a layer above both macOS and the app itself. For Slack and Microsoft Teams, Chirpy intercepts incoming notifications and plays a different sound based on rules you define — by channel, by person, or by keyword. This works even when the app itself doesn’t support custom sounds, like Teams on macOS.