High-powered automobile stereos

We measured the owner-adjusted acoustic outputs of 10 automobile stereo systems, with power ratings ranging between 150 and 600 watts. The sound levels ranged from 107 to 138 dB SPL and 84 to 108 dBA. Most of the high-intensity sound was in the 31, 62, and 125 Hz center-frequency octave bands. The mean computed noise dose, based on the vehicle owners' reported daily duration of exposure, was 108.5%. While there is clearly a risk of hearing damage in the extreme cases according to OSHA standards, the typical listening durations claimed by the stereo owners would seem to lower the risk for the majority to acceptable margins for the automobiles measured.