Sounds can help improve the enjoyment and overall feel of an OS.
In BB10, it would be great to have more sounds throughout the OS than playbook OS 2.0 has.
Sounds for...
Sending a message
Deleting messages
Closing apps
Volume change (hardware buttons)
Etc...
Maybe not all of these functions, or maybe even more. Bottom line, simple things like interface sounds can improve the OS
While there needs to be more sounds than on the PlayBook, I personally find sound effects to sending a message and stuff are annoying and would immediately mute them all.
I don't need a auditory response for when I unlock my phone