A medical instrument includes a sound card or an internal capability for generating sounds from a digital music or sound file. The medical instrument is one which generates unwanted noise and is constantly in the presence of a patient or an operator, and may be in a home, a clinic, a laboratory, or other intimate setting. For instance, a patient may be typically connected for hours to a hemodialysis machine that has a noisy pump. A blood-plasma volunteer may be hooked to a noisy blood separation machine for a period of time. A laboratory technician may work in close proximity to a sample preparation machine that constantly gurgles and whirrs. In each instance, a sound card and a speaker can generate previously-recorded masking noises that make that the presence and operation of the machine more tolerable.