Hyperacusis is a reduced tolerance to sounds. Like tinnitus, hyperacusis is a symptom, not a disease. Research in 2014 distinguishes between four different types of hyperacusis:
- Pain hyperacusis (also called noxacusis, auditory nociception or noise-induced pain): Sufferers experience physical pain, in their ears and surrounding areas, from sounds at a much lower volume than the average person. The normal threshold for pain from sound is between 120-140 dB. The pain is usually described as stabbing, burning, throbbing or a dull sensation.
- Loudness hyperacusis: Sufferers experience various sounds as being much louder compared to people with normal Hearing.
- Annoyance hyperacusis: Sufferers experience a negative emotional reaction to sounds.
- Fear hyperacusis: Sufferers experience a negative response to sounds, which can make them avoid situations where these sounds are present.
You can read a more detailed article about these subtypes.