While you might not be able to change the sound easily on all devices, you can highly customize the to reduce "notification fatigue":
The notification sound experience on is currently a point of frustration for many users due to limited direct customization options within the app itself. While you can manage what triggers a notification, changing the sound often requires navigating your device's system settings rather than the Threads app. The User Experience: Customization Limits Instagram Threads | Notification sound
Many iOS users have reported dissatisfaction with the default system "Rebound" sound, describing it as difficult to hear compared to previous tones. How to Manage Your Notifications While you might not be able to change