Key points:
  1. Because “two hearing aids work better than one”, we often recommend bilateral hearing aids for patients with bilateral hearing loss, whether it is symmetric or not.
  2. We often meet the cases in which only one hearing aid is permissible. Contrary to symmetric hearing loss, it is very difficult to choose an ear for unilateral amplification in AHL (asymmetrical hearing loss).
  3. This study showed that the hearing threshold of 1 kHz of the better ear had statistically significant effects on the success of hearing aid use.
  4. Etiology of sudden hearing loss and age were non-audiometric factor that had statistically significant effects on the outcome.
  5. To plan a fitting strategy for AHL, clinicians should keep in mind that patients with sudden hearing loss and younger patients should be encouraged to receive at least monaural amplification.