Tone deafness is the inability to discern between similar pitches, although people can usually tell the difference between radically different pitches. Rather than being a hearing impairment, it is the result of a cognitive processing disorder where the area of the brain responsible for handling sound is incapable of differentiating between sounds with very similar pitches. Many people refer to bad singers as “tone deaf,” but in fact very few people who sing poorly actually have amusia, the formal term for tone deafness; usually, their poor musical abilities are the result of a lack of training.
There appears to be a genetic component involved in tone deafness. While studies do suggest that some training is required to learn to differentiate tones, as seen in very young children who start to learn to distinguish and process speech with adult models to provide instruction, as well as musicians who receive advanced training in how to play musical instruments and sing, people who are truly tone deaf cannot be trained to tell the difference between similar pitches.
Some neurologists believe that the areas of the brain involved in processing musical pitch can also be part of speech processing, and express concerns about the implications of tone deafness for understanding and generating speech. Others believe this is not the case. Many studies looking at the connections between tone deafness and speech have examined cultures using tonal languages, where researchers who believe speech and music are connected would expect to find that tone deaf people would have trouble understanding speech. These studies have been inconclusive in nature.
Tests are available to see if people have an auditory processing problem leading to tone deafness. In the test, people listen to different pitches and excerpts of music and respond to prompts from the person administering the test. People can be asked if two tones are different or if a piece of music sounds off. If the person fails to distinguish music out of pitch or cannot hear the difference between two similar tones, amusia is the likely cause.
Having trouble hearing the difference between tones is not a significant disability, but it can potentially be a problem. People with tone deafness certainly cannot pursue musical careers and the ability to hear subtle variations in pitch can be important in other fields as well. Mechanics, for example, are very attuned to the sound of engines and can sometimes diagnose or identify problems on the basis of pitch variations or shifts in the sounds made by an engine.