About hearing loss
Hearing impairment is the amount of hearing loss relative to normal hearing for a person’s age and sex. It is measured by audiologists who test the Hearing Level (HL) of each ear using different frequencies. Hearing loss can be partial or total and can be caused by different factors.
During the test, an audiologist plays tones of different frequencies. The intensity of each tone is changed in order to find the lowest level that the person can hear.
Based on this test, hearing loss can be categorised as:
Mild hearing loss
Hearing loss of 20 to 40 dB HL. Normal speech can be perceived but people speaking in a low or quiet voice will be difficult to hear. Soft sounds cannot be heard. Understanding speech in noisy environments starts to be an issue. However, the majority of familiar sounds are still perceived.
Moderate hearing loss
Hearing loss of 40 to 70 dB HL. Moderate sounds cannot be heard. Speech is perceived if the speaker raises his or her voice. Hearing becomes easier if the person can see the speaker. Some familiar sounds are still perceived.
Severe hearing loss
Hearing loss of 70 to 90 dB HL. Speech is perceived when the speaker speaks loudly and is close to the ear. Only loud sounds are perceived. Following a group conversation is difficult.
Profound hearing loss
Hearing loss of 90 to 120 dB HL. It is not possible to hear any kind of speech and communication is impossible. Only very loud sounds are perceived.
Total deafness or cophosis
Above 120 dB HL nothing is perceived.
People are our starting point
A cochlear implant (CI) system transforms acoustic sounds into electrical stimulation for the auditory nerve.