Full-volume startup sound after 4.4 kernel update on 14.04

Since accepting the EOL prompt and applying all updates, my 9350 plays the startup sound at full volume every time I boot.

I can mute or turn the volum down completely before shutting down, no change

I can mute all sound effects, no change

It's really annoying to have the machine blast out the "doodledoot" sound every *** time. Anyone experiencing this? How do I turn off the startup sound?