- Auditory agnosia
Auditory agnosia is a form of
agnosia that manifests primarily in the inability to recognize or differentiate betweensounds . It is not a physical defect, but a mental inability to allow the brain to process what the sound means. Persons with auditory agnosia can physically hear the sounds and describe them using unrelated terms, but are unable to recognize them. They might describe the sound of some environmental sounds, such as a motor starting, as a lion roaring, but would not be able to associate the sound with "car" or "engine". [Human Neuropsychology. Neil Martin. Published by Prentice Hall, 2006. ISBN 0131974521, 9780131974524]Types of auditory agnosia
There are three primary distinctions of
auditory agnosia. "Linguistic (or verbal information or Wernicke's) agnosia" indicates that the subject can't comprehend words, although they can understand words usingsign language and words from reading books, and are themselves capable of speech (and even of deriving meaning from non-linguistic communication e.g. body language) ["The man who mistook his wife for a hat", Oliver Sacs] the particular sounds associated to each word are meaningless. [Neurolinguistics: An Introduction to Spoken Language Processing and Its Disorders. John C. L. Ingram,. Austin, J. Bresnan, B. Comrie.Cambridge University Press, 2007.ISBN 0521791901, 9780521791908]"Classical (or pure) auditory agnosia" is an inability to process environmental sounds, such as animal noises, industrial noises, or the like. An airplane roaring overhead would not be understood to be related to the idea of "airplane" -- indeed, the person would not even think to look up. [Clinical Neuropsychology. Kenneth M. Heilman, Edward Valenstein. Published by Oxford University Press US, 2003. ISBN 0195133676, 9780195133677]
"Interpretive or receptive agnosia (amusia)" is an inability to understand
music . The term 'Amusic' covers a broad spectrum: from those with a mere deficit of rhythmic ability (mild dysrythmia), to those with heavy all-encompassing Amusia, including the recently coined "Distimbria"; sufferers regard music as simply "noise", often compared to some form of other noise. Vocal singing can be understood, but is simply seen as "odd tone of voice". [Dictionary of biological psychology. Philip Winn. Published by Taylor & Francis, 2001. ISBN 0415136067, 9780415136068] The standard is considered to be that amusics with a "normal" intensity of amusia are cortically unable to distinguish pitch changes of less than three semitones. They may appreciate or enjoy listening to or performing music, but some can not tolerate it or find it irritating. ["Uses and functions of music in congenital amusia."McDonald, Claire; Stewart, Lauren.Music Perception (0730-7829)Apr 2008. Vol.25,Iss.4;p.345-355]NB. These are somewhat ambiguous definitions, and are changing all the time as they are updated to fit the current neuropsychological model of the physiological behaviours and manifestations of these deficits, and cannot therefore be considered a concrete meaning.
ee also
*
Agnosia
*Aphasia
*Apraxia References
*Disorders of Auditory Processing:Evidence for Modularity in Audition. Michael R. Polster and Sally B. Rose, 1998 (Psychology Department, Victoria University of Wellington, Wellington, New Zealand); summary by R. Walsh, Goldsmith's University of London
External links
* [http://www.psychnet-uk.com/dsm_iv/agnosia.htm DSM-IV Definition]
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