(Also known as Dysphonetic, Auditory or dysphonesia dyslexia) This kind of dyslexia is the most common and the person has difficulty in identifying phenomes i.e the sounds within words, and will have difficulty matching letters to sounds.
When trying to read they will make wild guesses at words and will struggle with nonsense words or fictional words that have been constructed from Proper names, Mnemonics, etc.
Greater difficulty will occur when spelling words and they will try to make sense of the illogical chaos and lack of comprehension they are experiencing. Their attempts to spell will include impossible letter combinations e.g. 'sfr'
Most tests for Dyslexia will include the requirement to read nonsense words e.g. 'sluft' and 'prenck'. This is to force the subject to read and sound out the letter combination as a word, revealing an underlying comprehension with letters, words and their construction. Also, it is thought to prevent the subject from simply guessing words they have heard rather than one's they have read.
This test and exercise is meant to determine whether a subject has a Phonological Dyslexia.