When skilled readers give children the wrong sounds, or fail to recognise when children have the wrong ones, 1 in 4 children are left behind. Inaccurate phoneme input disrupts orthographic learning. Words may be memorised for reading, but spelling, generalisation, and independent decoding do not develop. This happens in homes all over the country, but rarely do we see this, or acknowledge it. It's time we started better supporting parents of at risk children.  
 

Orthographic interference in action
 

1. Stored word knowledge overrides the spoken signal
Skilled readers do not access a word through speech when they see it. They are at the stage known as Orthographic Mapping. The spelling, pronunciation, and meaning are retrieved together as a single stored unit. When they look at a word, the spelling pattern activates the known pronunciation directly, rather than the adult consciously analysing the sounds in the word. When asked to “say the sounds,” they are not actually listening to the word as spoken. They are responding to what the word looks like.
 

2. The most frequent sound value wins
English phoneme-grapheme correspondences are probabilistic. Skilled readers internalise the most frequent sound value of a grapheme and apply it automatically. When a word uses a less common correspondence, the dominant one intrudes. The adult genuinely believes they are giving the correct sounds, but they are supplying the statistically strongest mapping, not the one that matches the word. We call this being 'blinded by the letters'
 

3. Visual form distorts phoneme awareness
Orthographic knowledge interferes with phoneme perception. Adults “hear” sounds that match the spelling they expect, rather than the sounds actually present in the word. This leads to added, removed, or reshaped phonemes, especially vowels. The child is then taught a sound sequence that does not match the spoken form they are trying to map.
 

4. Adults correct children away from accurate speech
When a child segments a word using the sounds they genuinely hear, an adult may override the child’s response because it conflicts with the adult’s orthographic expectation. The correction feels authoritative but is linguistically inaccurate. The child learns that their speech perception is wrong and begins to rely on guessing or memorisation instead of mapping.
It is vital that the adults are able to efficiently map words into speech sounds, and to do so according to the person saying the word. They should be able to identify the sounds in spoken words according to accent. 
 

5. Accent normalisation hides the error
Skilled readers unconsciously normalise pronunciation to their own accent or an imagined “standard” one. This masks phoneme-level differences and increases the chance of supplying a sound that fits the spelling rather than the child’s spoken form. The mismatch is subtle but cumulative.
We help adults become more aware of their own accent, and correctly map words for their accent, and do this for all accents.   
 

6. Fluency masks inaccuracy
Because the adult reads fluently, their explanation carries confidence. Neither the adult nor the child notices the error in the sound sequence. The word is read correctly, but the underlying mapping is wrong, so it cannot be reused for spelling or for reading similar words.
 

The consequence for children

Children can be given incorrect phoneme input, while their own inaccurate sound sequences go unnoticed. For children in Reception and KS1 who are at risk of dyslexia, this can be devastating.

Once the wrong sound sequence becomes attached to a spelling, orthographic learning is disrupted. The word may be read correctly through memory, but it cannot be spelled, generalised, or used to decode related words. The child appears to be coping, yet the underlying mapping is fragile or wrong.

Over time, repeated exposure to inaccurate sound–spelling links erodes confidence. The child stops trying to analyse words and instead relies on guessing or visual memory. By the time difficulties are recognised, the critical birth-to-seven window for preventing reading and spelling difficulties has often closed.