Definition

Most people with hearing loss have what is known as “binaural” hearing loss, meaning hearing loss in both ears. But some people may lose their hearing in just one ear. This is known as a “unilateral” hearing loss. If the degree of hearing loss is profound or near profound, it is known as single-sided deafness (SSD).

Cause

The hearing loss can develop either at birth or later in life and can happen over time or suddenly.

Some causes include the following:

  • Meniere’s disease
  • acoustic neuroma
  • viral or bacterial infection
  • diseases like Measles, Mumps and Meningitis
  • physical damage to the ear
  • head trauma
  • circulatory system disorders
  • genetic or inherited disorders
  • Sometimes a cause can’t be identified or is due to a combination of factors.

*When the hearing loss happens suddenly, it requires prompt treatment and should be considered a medical emergency. This is known as sudden sensorineural hearing loss and is described in more detail here.

Symptoms

Patients often report the following:

  • Difficulty with localization; they cannot pinpoint where sound is coming from
  • Struggling to hear in noisy environments
  • Having a harder time telling how loud a sound is
  • Struggling to ‘multi-task’

Treatment

For people with mild to moderate hearing loss, a hearing aid may be all that is required to amplify the sounds they are not hearing. Severe to profound single-sided deafness is often permanent, but sometimes treatable with devices worn on your functioning ear. Your audiologist may recommend a CROS, BiCROS, Bone-anchored Hearing Aid or Cochlear Implant.

The acronym stands for Contralateral Routing of Signals. With a CROS system, you wear hearing aids on both ears, even though you can’t hear from one of your ears. The sound detected by the aid on the ‘bad/deaf ear’ is transmitted directly to the aid on the ‘good ear’ side.

BiCROS hearing aids work the same way, except they are designed for people who have a hearing loss in their ‘good ear’, too. This means the ‘good ear with hearing loss’ now receives the sound from the ‘deaf ear’ side in an amplified way.

Some people do not find CROS or BiCROS hearing aids helpful. An alternative is a bone-anchored hearing system, which requires surgical implantation. These devices send sound vibration directly to the inner ear through the skull bone, a process known as bone conduction. This can be helpful because it circumnavigates problems in the middle ear and ear canal that prevent sound from reaching the inner ear. In those cases, standard hearing aids may not be effective.

A cochlear implant is a surgically implanted electronic device that provides the sensation of sound for people with severe and profound hearing loss. You can read more about it here.