Hearing loss refers to a diminished ability to hear sounds like other people do, while deafness refers to the inability to understand speech through hearing even when sound is amplified. Profound deafness means the person cannot hear anything at all; they are unable to detect sound, even at the highest volume possible.
Degree of hearing impairment – a person’s severity of hearing impairment is categorized by how much louder than “usual levels” sound volumes need to be set at before they can detect a sound.
Degree of deafness – any degree of deafness means the person cannot understand speech through hearing at any level of amplification. If a person is profoundly deaf, they cannot detect sounds at any volume. Some people define profoundly deaf and totally deaf in the same way, while others say totally deaf is the end of the hearing spectrum.