Set a max volume for the Terminal bell
You can change the system alerts sound level by this way:
- Go to the "gear cog" in the upper right corner of the screen.
- Select System settings...
- Click on Sound.
- Click on the Sound Effects tab.
- Lower the Alert volume to a comfortable level (or mute it).
Here you're a screenshot:
The following prevents the readline(3) program used by bash(1) to beep when encountering an alert character (ASCII=7).
$ echo "set bell-style none">> ~/.inputrc