Long Description: This graph compares responses between a standard audible detector and a low frequency audible detector among hearing, hard of hearing, and deaf participants. The low frequency alarm had much better results among the hard of hearing compared to the audible detector (~92% compared to ~56%). By lowering the sound frequency, there was a 35% increase in alarm waking effectiveness among the hard of hearing. The 11% waking effectiveness in the low frequency audible detector measured among the deaf subjects is due to those two people with residual hearing in the frequency range of the low frequency detector.