Tone deafness -- or amusia – can be congenital, present from birth, or acquired following injury to the brain.    From Wordnik.com.  [Science and a bit of snoopery] Reference

In a new study, researchers now report the first objective measurement of the brain deficit in congenital amusia.    From Wordnik.com.  [Science and a bit of snoopery] Reference

Delves into amusia tone deafness, music therapy, musical hallucinations, imagined music, musically-induced seizures and more.    From Wordnik.com.  [Musicophilia] Reference

Loved this from the article: Ms. Barker has the condition amusia despite the fact that her parents own a store specializing in traditional Irish instruments.    From Wordnik.com.  [Musical Minds, on PBS's Nova] Reference

~ Brain changes associated with congenital amusia -- About four percent of the population has congenital amusia, a lifelong disability that prevents otherwise normal functioning individuals from developing basic musical skills.    From Wordnik.com.  [Speedlinking 11/30/07] Reference

Cheryl has lost all appeal she may have had with her complete amusia every week.    From Wordnik.com.  [Irish Blogs] Reference

Using SSIRH one is able to explain why there are occurrences of isolated amusia or aphasia.    From Wordnik.com.  [Citizendium, the Citizens' Compendium - Recent changes [en]] Reference

The opposite is true of the less than 1% of the population who suffer from amusia, or true tone deafness.    From Wordnik.com.  [TIME.com: Top Stories] Reference

To bring this back around to the original point, any enforced political dystopia must be rooted in a kind of existential amusia, in which one has lost the ability to detect the rhythm, melody, and harmony of history.    From Wordnik.com.  [One Cʘsmos] Reference

The medical profession is still investigating the cause of amusia and it is possible that there is a genuine affliction that disables the ability to distinguish musical intonation, but in the vast majority of cases, even the most excruciating singer can be taught to sing in tune.    From Wordnik.com.  [Telegraph.co.uk - Telegraph online, Daily Telegraph and Sunday Telegraph] Reference