Metaphon (Dean & Howell, 1986; Dean, Howell, Hill & Waters, 1990; Dean, Howell, Waters & Reid, 1995) is based on the principle that homophony motivates phonemic change.

Phonological analysis is performed using the test in the Metaphon Resource Pack (or the phonological assessment of choice) and errors are described in terms of phonological processes. Target vs. substitute sound pairs are selected for treatment. Feature contrasts are usually minimal or near-minimal. The essence of Metaphon is in two overlapping treatment phases followed by a discrete final phase.

Metaphonetic skills are trained to improve a child’s ‘cognitive awareness’ of the properties of the sound system, while metalinguistic tasks are used to develop more successful use of repair strategies.

Metaphon Phase 1

The child is taught that language is used to communicate, and that language which is normally opaque can be made transparent or tangible. Phase 1 comprises Concept Level, Sound Level, Phoneme Level and Word Level.

Phase 1 is the most important phase of Metaphon, and the one most distinct from other published phonological intervention programmes. The aim is to capture the child’s interest in the phonology of the target language, to alert the child to the properties of sounds and their contrastive potential, to show that contrasts between sounds convey meaning and to facilitate the child’s knowledge that these features can be manipulated to increase the likelihood of being understood.

At Concept Level individual speech sounds are not contrasted and the child learns a conceptual vocabulary to use later for PVM awareness, e.g., Mr Noisy or Mr Growly to denote voiced consonants, Mr Whisper or Mr Quiet for voiceless ones. Other concepts such as Long Sound vs. Short Sound; Back Sound vs. Front Sound are introduced, with the aim of having children identify sounds by their properties with 100% accuracy.

The Metaphon team reported that it may not take long for children to achieve this level of accuracy.

The next step is different depending whether substitution processes (e.g., Fronting, Stopping, and Gliding where one sound replaces another) or syllable structure processes (e.g., Weak Syllable Deletion, Cluster Reduction, Final Consonant Deletion in which the structure of the syllable changes) are being targeted.

Substitution processes

For substitution processes, at Sound Level the vocabulary the child has learned (Mr Growly, Short Sound, etc.) is transferred to describing non-speech sounds: castanets, whistles, the therapist’s vocalisations, and animal and vehicle noises. The aim is to show the child that environmental sounds and vocalisationscan be classified as long-short, front-back and noisy-whisper (growly-quiet).

Then, at Phoneme Level entire sound classes are contrasted, using visual cues. For example, all fricatives vs. all stops are presented to the child, still referring to the sound properties (long-short etc).

Next the child enters Word Level and minimally contrasted word pairs are introduced for listening (not production). The child judges whether a word has a long-short, front-back, noisy-whisper sound in it. Again, visual support is provided in the form of gesture cues and pictures.

Syllable structure processes

For syllable structure processes at Sound Level concepts such as beginning (as a preparation for working on ICD), end (preparatory to tackling FCD) are introduced, as well as imagery and concrete demonstrations. For example, for Cluster Reduction SIWI imagery coupled with a concrete demonstration might involve a train with one locomotive vs. a train with two locomotives in preparation for a near minimal pair such as rip-trip. Or, you might have a train with no engine (art) vs. a train with one engine (tart) vs. a train with two engines (start). At Syllable Level / Word Level nonsense syllables and words are contrasted, e.g., hot has an engine, ot does not.

Metaphon Phase 2

In Phase 2, metaphonological tasks involving minimal pairs (introduced in Phase 1) and homonymy confrontation are emphasised, and the focus shifts to developing communicative effectiveness by giving the child feedback about success or failure to convey meaning, through behavioural responses, prompting him or her to review output. Dean and Howell (1986) postulated that, in the short term, such feedback would improve production by triggering the use of repair strategies based on the new knowledge of sound contrasts learned in Phase 1, and that the long term effect would be a change in central phonological processing.

Phase 2 is concerned with developing phonological and communicative awareness, and the link between phases one and two is achieved by incorporating Phase 1 activities into Phase 2. Phonological awareness and awareness of the properties of speech sounds must be well developed before the core activity of Phase 2 can be successful.

Metaphon Core Activity

In the core activity the clinician and child take turns to produce and select minimal pair words (e.g., pin vs. fin) pictured on cards or worksheets.

If the child says a target word such as fin, correctly:

  1. The therapist selects the correct word;
  2. Feedback is given;
  3. Guided discussion occurs: e.g., ‘Yes. That was a long sound. I guess you know lots of other long sounds.’

If the child says the target word incorrectly (e.g., bin for fin)

  1. The therapist selects the incorrect word (the one the child said);
  2. No feedback is given directly to the child, but the child’s attention is drawn to the sound property, e.g., ‘That was a short sound. Should it have been a long sound?’

The aim of the core activity is to have the child revise incorrect productions ‘spontaneously’.

Metaphon Final Phase

In the final phase, minimal pair sentences are introduced. The therapist and child take turns: each instructing the other to, for example, ‘Draw a pin/fin on the fish’; ‘Draw a pan/fan in the box’; ‘Draw a pole/foal in the stable’. Emphasis is still on guided discussion of sound properties (‘I think that should have been a long sound’) aimed at facilitating the spontaneous use of repair strategies.


Dean, E., & Howell, J. (1986). Developing linguistic awareness: A theoretically based approach to phonological disorders. British Journal of Disorders of Communication, 21, 223-238.

Dean, E., Howell, J., Hill, A., & Waters, D. (1990). Metaphon Resource Pack. Windsor, Berks: NFER Nelson.

Dean, E.C., Howell, J., Waters, D., & Reid, J. (1995). Metaphon: A metalinguistic approach to the treatment of phonological disorder in children. Clinical Linguistics and Phonetics, 9, 1-19.