Abstract: A portable air horn apparatus. The apparatus includes an air horn adapted to generate sound when supplied with air under pressure, an air compressor adapted to generate air under pressure, an air conduit interconnecting the compressor and the air horn enabling the air under pressure generated by the compressor to be supplied to the air horn, an electric motor adapted to operate the air compressor when energized, a portable source of electrical energy, and electrical circuitry electrically connecting the portable source of electrical energy to the electric motor to enable the electric motor to be energized. The circuitry includes a manually operable on-off switch having a first position opening the circuitry and a second position closing the circuitry. A housing is provided for physically supporting and interconnecting at least the air horn, compressor, electric motor, on-off switch and portable source of electrical energy, and includes a handle adapted to be manually graspable by a user of the device.