This java applet is a demonstration of digital filters. You should hear a noise waveform when the applet starts up. If you get a message "Need java 2 for sound", then you should get the Java plug-in. The applet starts up with a low-pass filter.

Bass boost is an audio effect to boost or amplify low frequencies of the sound. It is comparable to a simple equalizer but limited to one band amplification in the low frequency range.