There's a study that predicts emotional sensitivity to and processing of pain and painful experiences based on measurements of resting-state functional connectivity patterns in the brain 3-5 days prior. It does not specifically correlate to stuttering, but it's interesting to observe such predictions over infradian rhythms. I do not believe it's necessarily triggered or that watching out for immediate triggers might help. Certain scenarios might make it worse as perceived threat increases in magnitude, but I would consider this a multiplier rather than the base value (metaphor for a sort of binary 0/1 YES/NO proclivity to stutter). Hearing our own voice, or auditory feedback, is a precursor. My hypothesis on this is it doesn't even take hearing our own voice. In anticipation of our turn to speak in front a group or whatever stressful scenario, our breathing changes and becomes audible to us. This might serve function of the role of the right hemisphere in regulating the tone and pitch of our voice. Logic would have it that if it's control of our speech we are after, we tune to hear and follow the rhythm of our own breathing prior to the speaking event. This is my own hypothesis I have been entertaining recently. Outside of my own take and as a sort of supplement to it, I found this study interesting, if you haven't already read: URL=https://www.frontiersin.org/articles/10.3389/fnhum.2021.662204 Prior to the speaking event, based on previous stuttering experiences, the brain might anticipate an oxygen-scarce environment. "In the “classical model,” there are two main pathways for glucose metabolism: an aerobic pathway, involving the mitochondria, and an anaerobic pathway, resulting in lactate as a (supposedly) harmful waste product. Both pathways produce adenosine triphosphate molecules (ATP) as fuel for the cells, though the aerobic process is 19 times more effective for ATP production than the anaerobic process. Therefore, the anaerobic pathway has been considered to only have the function of providing emergency support when the supply of oxygen is insufficient." Anaerobic we typically utilize for activities that require short and explosive bursts of energy, as in lifting weights. Going by the low-intensity muscle contractions over higher time durations required for speech, the aerobic process is what's optimal.