Phonics: Long and short vowels, and the influence of the vagus nerve
8 November 2023
Obviously, it is important that ALL children learn to read well. However, the lowest attaining twenty per cent of children are less likely to become confident, fluent readers. As a consequence, schools must monitor the development of pupils’ progress in phonics.
It is essential to identify any pupil who is falling behind the pace of the school’s phonics programme and to put effective support in place, but the quality of such support must withstand scrutiny. A certain amount of cognitive bias has been identified and found to disadvantage the lowest attaining children. Much of this is centred around verbal interactions - ie the spoken words between teacher and pupil. These verbalisations can be heard as criticism of the pupil and bias has also been found in the subtle manner in which expectations of the pupil are voiced.
In the teaching of early reading, communicative approaches are considered to have significantly positive effects. It is therefore important that when teachers are engaged in modelling language and reasoning, extending vocabulary and drawing attention to letters and sounds, they guard against cognitive bias, particularly in schools that serve disadvantaged communities. Given that unconscious bias can influence the way a child learns, it is important to understand how the emotional cues or ‘tone’ of the voice intersect with the human nervous system in the teaching of early reading.
Image credit - Michal Parzuchowski via Unsplash
What is phonemic awareness and how important are long and short vowels?
Phonemic awareness and decoding are essential for the development of reading. After all, as research has shown - guessing words from their context is only accurate for ten to twenty per cent of the time. As the foundation of a systematic approach to the teaching of reading, phonemic awareness and the alphabetic principle need to be explicitly taught until they become automatic.
The principle of automaticity is key to the development of good reading. When the reader has internalised the correspondence between letters and their sounds, the cognitive load lightens and frees up capacity in working memory, as well as cognitive attention. As availability of both memory and attention expands, the reader engages with the text with increasing fluency, ease and understanding.
However, as each word consists of a unique combination of phonemes and each syllable is characterised by a vowel sound, awareness of the differences between long and short vowels can make or break the development of phonemic awareness. Why is this? Well, vowel sounds are particularly interesting because they carry information about the meaning assigned to a word, and in everyday speech, they also carry the speaker’s tone of voice, as well as their attitude or intention towards the listener, including any cognitive bias.
Arguably, if the sounds of vowels are associated in the mind of the child with feelings of confrontation, then the vowel sound may trigger an anxiety-inducing response that does not support learning.
What is the vagus nerve?
The vagus nerve relays sensory information that helps us to perceive the physiological signals that inform the brain of our internal state. As a cranial nerve, it connects the brain with almost every organ of the body and although the information travels in multiple directions, the majority of it flows upwards from the body to the brain. Certain parts of the vagus nerve are important for speech and are discussed below.
The vagus nerve descends on the left and the right of the neck. It innervates both sides of the larynx before it drops down into each side of the chest and then passes back up into the neck and into the larynx. On this ascending pathway the vagus nerve innervates all the remaining intrinsic muscles of the larynx, which are responsible for opening and closing the vocal folds. The nature of this return journey may account for why these branches of the vagus are known as the recurrent laryngeal nerve.
The larynx
The larynx (or voice box) has three important functions. One is to prevent us from inhaling food or liquids. Another is to support breathing. The third is to produce sound through speaking, singing, shouting and screaming. The muscles of the larynx adjust the length and tension of the vocal folds (vocal cords) and this is how people adjust the tone and pitch of the voice, though the nervous system usually takes care of this for us subconsciously.
The tone of voice can be modified to portray a wide range of emotions such as anger, fear, surprise, sadness and joy. In stressful situations, chronic tension in the larynx can arise and can weaken the coordination between the muscles controlling the vocal folds.
The job of the cricothyroid muscles is to tense the vocal cords, resulting in more forceful and higher pitch speech. This is the only muscle that is innervated by the superior (upper) laryngeal branch of the vagus nerve. This muscle fundamentally changes the main acoustic of the sound, in terms of the emotional content and the contrasts in tone.
The more gentle sounds of the human voice are produced by the muscles innervated by the recurrent laryngeal nerve, after it has travelled through the chest area. These muscles include:
The thyroarytenoid muscles, which relax tension and shorten the vocal folds.
The posterior cricoarytenoid muscles, which widen the space between the vocal cords and pull them away from the midline of the body.
According to research findings by Arnal and colleagues (2015), human screams exploit a unique acoustic property. They display a ‘roughness’ that activates not only the brain’s auditory system, but also the amygdala, a deep brain structure that is involved in processing fear and danger.
A scream is a long vowel sound, ‘ah’, characterised by its high pitch and initial loudness. The researchers showed that a scream is distinctive (when compared to high pitched singing) because of its rough rather than harmonious qualities. It is the roughness that produces the fear-inducing response in listeners. However, context is key. In school playgrounds, under adult supervision, many children let off steam by running fast and screaming as they chase each other. This is a healthy use of the voice to release emotion in a playful way. A fast-paced and playful environment with a lot of emotional release reinforces active coping strategies and builds resilience as well as social connection.
The vagus nerve, which ascends through the vocal folds, and into the brain innervates two areas that are important for managing emotional and physiological pain: the insula and the anterior cingulate cortex. Given that our tone of voice can indicate how we feel in our social environment, and how we feel influences how we learn, how might this information apply to the way we approach vowels in the teaching of early reading? Let’s first consider vowel sounds in the context of phonemic awareness.
How are long and short vowels related to the vagus nerve?
The emotion in the voice is related to the variability of vowel sounds as well as vowel length and impacts the vagus nerve in the following ways.
Social engagement and learning
Given that the majority of our learning (via peers, experts, books or online media) is social, it’s interesting to know that the ventral part of the vagus nerve allows us to feel comfortable whilst we are socially engaged. This part of the vagus nerve is located towards the front of the body and opens up the heart space, allowing us to breathe more deeply. This is how the vagus nerve supports our ability to communicate easily with others. It ensures that we feel regulated and can handle what’s happening. In this socially engaged state, the voice shows variation in rhythm and pitch. An extreme example of this can be heard in the exaggerated rise and fall of the voice, as well as the lengthening of vowel sounds when parents interact with their young children. These particular sounds encourage feelings of safety and achieve an ideal environment, particularly for acquiring the child’s first language. In the majority of socially relaxed situations, people smile with their eyes and produce a calm friendly voice with warmth in both longer and shorter vowel sounds.
Confrontational behaviour and learning
When people feel threatened, learning continues as part of an active coping strategy, but this is a different kind of learning. There’s tension in the shoulders and the sides of the ribs are constricted. The jaw may be clenched and speaking will feel reactive and sound lower in pitch. The vagus nerve enables these changes by allowing the heartbeat to pick up pace as a reaction to a perceived threat or stressor. Learning therefore takes place in a competitive rather than an exploratory context. There’s potential for the individual to overcome the threat through assertiveness. There can be confrontation, criticism and aggression in the voice, as the rise and fall of a socially engaged voice has been replaced by a more defensive tone, with a distinctive roughness in the vowel sounds. Assertiveness may or may not prove to be a successful strategy, but either way, the behaviour and outcome are appraised and stored as a memory.
Defeated behaviour, dysregulated behaviour and learning
If a situation is intolerable, feelings of flight and anxiety increase arousal levels and produce shallow, fast breathing and a relatively high pitched, faster pace of speaking. A low-level sense of dread limits focus, absorbs attention and constrains learning, whereas the most passive coping strategy of all involves the dorsal branch of the vagal nerve, which decreases arousal by freezing behaviour to such an extent that the person’s own voice feels unavailable and socialising is unimaginable. Learning is impossible in this state, as the body is too busy conserving energy: it is difficult to imagine doing anything, but survive.
Concluding thoughts
Given that we are ‘wired’ to learn and to be social, it’s essential to understand the importance of tone of voice. The tone of voice can trigger a response from the vagal nerve and if the voice is perceived as threatening, this will impact learning. The teaching of vowel sounds in a phonics programme must be undertaken with awareness of the role of the voice, particularly in terms of tone quality. Any abrasion in the voice is likely to impact learning in very young children. So, let’s avoid an abrasive vocal tone in the teaching of reading and instead, allow ourselves to engage in that melodious sing-song voice that children find reassuring, because this signals safety for ALL children during the teaching of early reading.
A child with sensitivity to rhythm is attuned to the onsets of the smallest sounds of language. In terms of rhythmic precision, the front edge of the sound is also the point at which the rhythmic boundary occurs. Children with a well-developed sensitivity to rhythm are also attuned to phonemes and are less likely to conflate the sounds.
Vowel sounds carry interesting information such as emotion, or tone of voice. They are longer (in milliseconds) and without defined edges. Now imagine focussing on the onset of those syllables. The consonants are shorter (in milliseconds), more sharply defined and more distinctive, leaving plenty of headspace for cognitive control. If consonants are prioritised, information flows easily and the message lands with clarity.
There is no doubt that the foundation of a good education, with reading at its core, sets children up for later success. The importance of phonics is enshrined in education policy in England and lies at the heart of teaching children to become confident, fluent readers. However, young children are not naturally predisposed to hearing the smallest sounds of language (phonemes). Rather, they process speech as syllables strung together as meaningful phrases.
Reference
Arnal LH, Flinker A, Kleinschmidt A, Giraud AL, Poeppel D. Human screams occupy a privileged niche in the communication soundscape. Curr Biol. 2015 Aug 3;25(15):2051-6. doi: 10.1016/j.cub.2015.06.043. Epub 2015 Jul 16. PMID: 26190070; PMCID: PMC4562283.
