Sound volume fluctuates abnormally when playing sound files

[Donald Skinner]

I am running a Windows XP guest on a Windows 7 64-bit host. I have noticed that when sounds play, it is as if there is an auto-level control functioning. When the sound is loud, the machine suddenly cuts the volume back slightly, and when the sound track become quieter, it noticeably brings it back up again. Listening to an extended piece of music is quite unsatisfying because of this constant volume fluctuation.

The phenomenon is much like auto-leveling on a computer microphone: if I'm too loud, the volume control is lowered. If I'm too quiet, the volume control is raised. But in this case with playback of sound files, it interferes with proper listening.

Attached is a log file of a normal boot and shutdown.

[Donald Skinner]

Normal boot-up and shutdown

[Donald Skinner]

Please consider my question closed. The issue resulted from a sound card setting in Windows 7, and Virtual Box somehow accentuated the effect. However, it was not a problem with Virtual Box after all.

[Sander van Leeuwen]

Thanks for the feedback.