definition of deaf and hard of hearing
If you are unable to detect sounds quieter than 90dB HL, the hearing loss is considered a profound hearing loss for those frequencies. If the average of the frequencies at 500Hz, 1000Hz, and 2000Hz is 90dB or higher, the person is considered deaf. A person who is hard of hearing can have a range of hearing loss from mild to severe. It should be noted that amplification technology is available for people with mild to profound hearing loss.