Debian: dmesg output contains “Error: Driver ‘pcspkr’ is already registered, aborting…”

Warning: Use of undefined constant user_level - assumed 'user_level' (this will throw an Error in a future version of PHP) in /homepages/3/d98111892/htdocs/insanelabs/htdocs/wp-content/plugins/ultimate-google-analytics/ultimate_ga.php on line 524

Here is what’s transpiring: the boot sequence attempts to load two different drivers for the integrated PC speaker. To solve the problem install alsa-base package:
aptitude install alsa-base

And then execute the following command:
echo blacklist snd-pcsp >> /etc/modprobe.d/alsa-base-blacklist