Frequency Control
Playback Mode
Hearing Range Guide
Mosquito Tones
Tones above 17.4kHz are called "Mosquito" tones because typically only people under 25 can hear them. They are sometimes used to deter loitering in public spaces.
Presbycusis
Age-related hearing loss (Presbycusis) is the gradual loss of hearing in both ears as we age. Higher frequencies are usually the first to go.