The Different Types of Hearing Loss

doctor-using-otoscope

The Different Types of Hearing Loss

Hearing loss is a common condition that can affect anyone regardless of their age, gender, or race. It can happen in any part of the ear and the experience can differ from person to person due to the cause and type of hearing loss. The different types are: conductive, sensorineural, mixed, and auditory neuropathy. In order to know which type one may have, we have to look at where and how hearing can be damaged. 

Sensorineural Hearing Loss (SNHL) 

Takes place in the inner ear when the auditory nerve is damaged, thus preventing signals (sound waves) from being sent to the brain for interpretation. 

Possible causes of SNHL:

  • head trauma 
  • ear-damaging medicines (ototoxicity)
  • illnesses like measles, meningitis, and some autoimmune disorders 
  • malformation in the structure of the inner ear 
  • genetics 

People with SNHL and no other underlying conditions may benefit from hearing aids, the most common treatment recommended by experts.

Conductive Hearing Loss 

When sound cannot get through the outer and middle ear. The damage is blocking the sound from reaching the inner ear. Thus, loud sounds may be muffled and soft sounds may be a bit of a struggle to hear. 

Conductive loss can be triggered by any of the following factors:

  • wax buildup 
  • trauma to the ear 
  • foreign object jammed in the ear 
  • ear infection 
  • tumors, in rare cases 
  • perforated or ruptured eardrum 
  • structural malformation in the ear parts 
  • accumulated fluid in the middle ear caused by allergies or colds 
  • poor Eustachian tube function (that prevents the fluid from draining from the middle ear)

Unlike SNHL, conductive loss can be detected and treated with medicine or surgery. After treatment, the patient can hear completely or partially depending on the degree of hearing loss.

Mixed Hearing Loss 

True to its name, this is a combination of SNHL and conductive hearing loss. The inner ear problem is known to be irreversible, while the outer or middle ear worsens hearing. Conductive loss may be treated, but the patient may likely need hearing aids following the treatment to help manage the lingering SNHL.

Auditory Neuropathy

This hearing disorder occurs when the inner ear successfully perceives sound but has problems transmitting signals from the cochlea to the brain. Auditory neuropathy can fluctuate from normal to profound, making it particularly difficult to comprehend speech clearly with noise in the background. 

Auditory neuropathy can affect people of all ages, from infants to adults. People with auditory neuropathy may have difficulty understanding speech clearly. 

Causes of auditory neuropathy include: 

  • damage to the auditory system 
  • jaundice 
  • lack of oxygen at birth 
  • inherited genetic mutations 
  • some neurological conditions

 

When Describing Hearing Loss:

Unilateral – this is only in one ear.

Bilateral – this is in both ears. 

Pre-lingual – this occurred before the person could talk.

Post-lingual – this occurred after the person learned how to talk. 

Symmetrical – this is the same in both ears.

Asymmetrical – this is different in each ear.

Progressive – this worsens over time.

Sudden – this occurs very fast or all of sudden.

Fluctuating – this changes between getting better or getting worse over time.

Stable – this remains the same over time. 

Congenital – this is present at birth. 

Acquired/Delayed Onset – this occurs later in life. 

Source: CDC.GOV: Types of Hearing Loss

 

The Different Degrees of Hearing Loss:

Mild: This is the most common and under-diagnosed level of hearing loss. Individuals with mild loss can clearly hear sounds more than 40 dB but will find it difficult to hear sounds below that level. This means that they can communicate well in one-on-one settings with a couple of people, but will have difficulty hearing over the phone or in a group setting with noisier environments.

Moderate: Individuals will have trouble hearing sounds at 60 dB and below. Since normal conversations typically sit between 50 and 65 dB, the person with moderate loss will have to strain often to keep up with the conversation without hearing aids or other listening devices.

Severe: Someone who is diagnosed with severe loss will have trouble hearing sounds below 80 dB, such as the sound of a hair dryer or a vacuum cleaner, which are both at 70 dB. Hearing aids would be a great help to people with this degree of hearing loss.

Profound: At this degree, individuals will most likely not hear any speech, but only very loud sounds. Even with hearing aids, they will still have trouble hearing and following conversations and will often resort to lip reading or sign language to communicate. A cochlear implant can improve their hearing condition, as it can be surgically inserted into the ear to replace the extremely damaged cochlea. 

Click on the links below to find out more:

ASHA: Types of Hearing Loss

ASHA: Type, Degree, and Configuration of Hearing Loss