Hearing loss varies from person to person. Hearing loss is described by characteristics hearing impairments. Some descriptive characteristics hearing impairments include severity, type, and onset. The cause is one of the characteristics of hearing loss.

The severity of the hearing loss is measured using hearing tests. The results of a hearing test should indicate the frequencies and lowest volume that the person can hear. Normal hearing is described by a hearing threshold of -10 to 15 decibels. A slight hearing loss is described as 16 to 25 decibels. A person who can only hear sounds that are 26 to 40 decibels and above is considered to have mild hearing loss.

The person’s hearing loss is described as moderate hearing loss if the lowest sound they can hear is 41 to 55 decibels. If the lowest sound that can be heard is 56 to 70 decibels, the hearing loss is called moderately severe. Severe hearing loss describes a person’s hearing loss when the lowest sound they can hear is 71 to 90 decibels. If the lowest sound the person can hear is above 90 decibels, the hearing loss is described as profound.

A characteristic of hearing impairments is that the hearing impairment may only affect the hearing of certain frequencies of sound. A hearing test may identify an inability to hear certain frequencies. An inability to hear high frequencies may be described as high-frequency hearing loss.

The onset of the hearing loss is one of the characteristics of hearing impairment. The hearing loss may have started gradually or may have occurred suddenly. A hearing loss that occurred unexpectedly and suddenly may be referred to as sudden hearing loss. The hearing impairment may affect one ear or both ears. If it affects one ear, it is called unilateral hearing loss. Bilateral hearing loss is a hearing impairment of both ears.

Hearing loss can be described as conductive, sensorineural, or mixed. Conductive hearing impairment is caused by a blockage of sound from the outer ear to the inner ear. Sensorineural hearing loss is characterized by the impaired ability of the cochlea or auditory nerve to send the sound messages to the brain. Mixed hearing impairment is the presence of both conductive hearing loss and sensorineural hearing loss.

Sometimes, hearing loss is described by what caused the hearing loss. For example, occupational hearing loss is hearing loss caused by working around loud noise. If the cause is unknown, the hearing loss may be called idiopathic hearing loss.