Decreased sound tolerance (DST) is a group term to describe 3 distinct sound sensitivities:
HYPERACUSIS refers to a discomfort around louder environmental sounds such as traffic, kitchen appliances, crockery/cutlery banging, laughter, TV commercials, music and group events. Individuals with hyperacusis will reacts by covering their ears, crying, removing themselves from the situation and over-use of earplugs. It typically occurs as a result of too much amplification of the auditory system.
MISOPHONIA refers to an extreme annoyance and emotional reaction to softer sounds, most typically mouth-related noises such as speaking, eating, chewing, lip-smacking and also repetitive, tapping and clicking sounds. Reactions can range from being irritable to sharp verbal outbursts and violent reactions. It typically occurs as a result of a hyper-reaction by the emotional and safety parts of the brain to sound.
PHONOPHOBIA refers to the avoidance of specific sounds by avoiding environments such as loud restaurants, movies, group gatherings or by avoiding a specific sound itself by avoiding specific people or avoiding eating with others, removal of cutlery/crockery sounds or use of sound-dampening devices. It typically occurs as a result of a fear of sound causing damage to the ear or brain.
All 3 types of DST can have a devastating impact on daily work and living by controlling an individual’s life as to where, when, why or who to engage with. The handicapping effects can often be extreme – from preventing an individual to enter a work environment, engage with family or friends and sometimes even result in discomfort with sounds from their own activities such as their own talking, shaving or showering. DST is often suspected where there is an unusual usage of hearing protection in environments or events where others are not typically using hearing protection.