This is Stackhouse and Wells' model of speech and language.
Input
'Physical sound wave' - a sound wave, whether speech or non-speech, occurs in the environment.
'Peripheral auditory processing' - the ear notices that a sound has been heard.
'Speech/non-speech discrimination' - the sound heard is classified as being either speech or a non speech sound.
'Phonological recognition' - speech sounds are classified as being part of a known language. 'Like tuning a radio until you reach a channel where you recognise the language.'
(Stackhouse and Wells, 1997)
'Phonetic discrimination' - unusual speech sounds are processed here. This is used when speech sounds differ from the expected 'norm', for example, when processing different accents and dialects.
Representation
'Phonological representation' - whole words are stored according to how they sound.
'Semantic representation' - the meanings of words are stored here.
'Motor programme' - the motor instructions required for speech muscles to produce the necessary sounds for words.
Output
'Motor programming' - allows the production of words not previously known: copying a nonsense word such as 'short'; this enables the learning of new words.
'Motor planning' - allows for factors about how a word will be said, for example, quickly, loudly or with specific intonation.
'Motor execution' - the speech organs are activated and a word is articulated.
This system of language processing enables a child to learn and produce new words. It can be subdivided into three broader processes.
Stage 1 - Input processing
- To learn to say a word the child must recognise similarities and differences between words; for example, tea/sea are different at the beginning, back/sock are the same at the end, sack/sock differ only by a vowel sound.
- To process these similarities and differences the child needs:
- good hearing;
- attention and listening;
- ability to recognise and process sounds.
Stage 2 - Representations (stores)
- A word is stored in our memory as a pattern of sounds; this store is structured and organised, each word has its own place.
- Sounds simple! But in fact it is very complex; words are grouped:
- words with the same first sounds
- words with the same end sounds
- words with the same syllable structure
- words that rhyme
- words with the same vowel
Stage 3 - Output processing
- The child must activate the movement of the speech organs such as lips, tongue, palate to produce the sounds required to form a word.
- The child must plan the movements in the correct sequence and send accurate messages to the muscles.
- The muscles and speech organs must then move in the required order to ensure the correct articulation of the word.
This is a model for single word processing. The child must also do the following:
- put a sequence of words together to make a sentence which makes sense and is grammatically correct
- understand the social use of language