Understanding Stuttering

Stuttering is the most common fluency disorder. It's an interruption in the flow of speaking — showing up as repetitions (of sounds, syllables, words or phrases), sound prolongations, blocks, interjections and revisions. It can affect the rate and rhythm of speech.

These interruptions can happen in typically developing speakers too — stuttering is more about how often, how long, and how much tension is involved.

When stuttering first appears in childhood it's called developmental stuttering. When it isn't of developmental origin, it's called acquired stuttering. Stuttering can also vary across time and situation — depending on the setting, who you're talking to, and what you're talking about.

Before thinking about stuttering, it helps to understand what "fluent" speech actually requires. Speaking is a complex process: the brain sends messages to the speech muscles to initiate movement and carry out a pre-planned sequence.

For fluent speech, the muscle movements involved in breathing, voice production (the voice box) and articulation (tongue, lips, jaw) all need to be well coordinated.

There's no single known cause. It's hypothesised that there may be reduced coordination in the muscle groups that control speech, with some research suggesting differences in timing control that are very slight — and show up when strong feelings or emotions "get in the way" and disrupt that coordination.

Stuttering is also thought to be neurologically based, involving brain regions that control motor planning, initiation and execution.

Cooper (1986) — stuttering involves more than just the overt, visible signs. We also need to look at the feelings, behaviours and thoughts involved.

The most basic speech behaviours of stuttering:

• Repetitions — of sounds, syllables or single-syllable words, often more than twice in an instance (e.g. "ba-ba-ball").
• Prolongations — a sound or syllable stretched out, with airflow and sound continuing (e.g. "mmmmmy ball").
• Blocks — usually the last core behaviour to develop; an interrupted movement of the articulators with a stoppage of airflow and voicing, typically lasting 1–5 seconds.

Reactions to core behaviours, which fall into two groups:

• Escape behaviours — a reaction to a dysfluency that's already happening; attempts to terminate it. Examples: eye blinks, head nods, interjections like "uh". These can end up being reinforced over time.
• Avoidance behaviours — used in anticipation of a dysfluency, to try to avoid stuttering and the negative feelings that come with it. This might mean changing a word, reformulating a sentence, or avoiding a situation altogether.

Many people who stutter develop negative feelings about their speech and about themselves as a speaker — commonly embarrassment, guilt, shame, fear and anger. Fear is often the most common feeling, and may attach to particular words, sounds, people or speaking situations.

Persistent fear and anxiety can lead to negative attitudes about oneself as a speaker, including self-blame and feelings of inadequacy. To avoid anxiety-inducing situations, a person may develop avoidance behaviours — which can end up reinforcing the belief that they're "incapable" as a speaker.

Only a small portion of an iceberg sits above the water — the rest lies hidden below the surface. Stuttering can be thought of the same way: the overt features (core and visible secondary behaviours) sit above the surface, while the covert or hidden features — negative emotions, thoughts and attitudes — lie below.

For many people who stutter, the visible signs are only a small fraction of the problem. The covert attitudes, feelings, thoughts and fears underneath are a large part of it, and can't be ignored.

Stuttering can be thought of on a continuum from covert to overt — hidden to open. Someone who stutters covertly experiences the cognitive and emotional side of stuttering while showing little or no outward signs — often by substituting words, avoiding situations, or even shaping career choices around fear of speaking.

Someone who stutters overtly shows behaviours that make it obvious to a listener most of the time. Stuttering openly can reduce the restrictions a person has placed on themselves — when it feels okay to stutter out loud, people often begin engaging in situations they'd previously avoided, and the focus shifts from complete fluency towards effective communication with less restriction.