I had this problem too with 8.10 on a desktop machine. I finally found the option under System > Preferences > Sound > Sounds. The options there seem a little less than intuitive to me. In my case I want a visual alert instead of a beep, so "Play alerts and sound effects" must be on but "Play alert sound" must be off.
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I had this problem too with 8.10 on a desktop machine. I finally found the option under System > Preferences > Sound > Sounds. The options there seem a little less than intuitive to me. In my case I want a visual alert instead of a beep, so "Play alerts and sound effects" must be on but "Play alert sound" must be off.