The document defines different levels of hearing loss based on threshold levels measured in a hearing test. Mild hearing loss occurs between 26-40 dB where soft sounds are difficult to hear but conversation is manageable. Moderate loss is 41-55 dB where background noise makes hearing difficult. Moderately-severe is 56-70 dB where speech clarity is reduced. Severe loss is 71-90 dB where normal speech cannot be heard and loud speech is difficult to understand. Profound loss over 90 dB means even amplified speech is difficult to understand.