Hi,
Unfortunately Ubuntu 12.04 LTS uses PulseAudio by default, which makes it hard to install and configure the Jack Audio Connection Kit that WINEASIO will use to connect to the sound system for low latency playing. So you are left with using DirectSound -> ALSA WINE drivers, and setting the buffer in Hauptwerk to at least 1024, maybe even 2048 in order to get non-distorted sound.
If you're willing to attempt an install of Jack and configure your computer to use the Low Latency Kernel which allows Jack to run at low latency realtime values, then mark the package 'ubuntustudio-recording' for installation. Use the quick filter to search for lowlatency and check the latest version of 'linux-image-lowlatency' for installation. This will then add the low latency kernel and add all the Ubuntu Studio audio packages including the Jack Audio Connection Kit with the PulseAudio connector, and should add the necessary audio group permissions needed to run them.
I no longer use Ubuntu, so there may be more steps needed to get everything running smoothly. I personally use Precise Puppy Linux, which is a much smaller/leaner distribution based on the Puppy Linux build system that integrates with the Ubuntu packages.
Also, I assume that you are starting Hauptwerk using the Free Edition setting, as if you are using either the Basic or Advanced demonstration settings then you will be hearing the bell ringing at various intervals
Kind regards,
GrahamG