Compaq Armada 7400 Reference Manual page 107

Some software applications, such as game programs,
include their own volume controls. You may need to
adjust the software volume controls to get the desired
sound levels.
The volume control on the computer overrides all other
software volume controls. That is, the volume from the
integrated stereo speakers, external speakers, or head-
phones will never be louder than the sound level selected
using the computer volume control.
Infrared-equipped computers are IrDA-compliant (4Mbps
standard). Infrared performance may vary depending on
performance of infrared peripherals, distance between infrared
devices, and applications used.
The infrared port on your computer allows wireless
communication between your computer or desktop
expansion base and other infrared-equipped devices.
Operating system support for infrared communication is
currently available with Microsoft Windows 95 and 98.
The infrared port uses an invisible beam of infrared light
to communicate with another infrared-equipped device.