When it comes to mastering new speech sounds, timing may be everything. Recent research by Anne van Zelst, Ph.D., assistant professor in the department of Communication Sciences and Disorders, and colleagues suggests that learning during non-optimal times of day could actually accelerate progress in speech motor learning.

The research, titled Harnessing Time: Leveraging Chronotype Synchrony and Asynchrony to Promote Efficient Speech Motor Learning, examined how alignment—or misalignment— with an individual’s natural circadian rhythm influences learning outcomes. Chronotype, the biological tendency toward morningness or eveningness, shapes alertness and cognitive performance. Traditionally, explicit tasks are thought to benefit from peak alertness, while implicit learning may thrive under less-than-ideal conditions.

To test this theory, van Zelst and her team recruited 74 native English speakers with typical speech and hearing abilities. After determining each participant’s chronotype using the Morningness-Eveningness Questionnaire, researchers scheduled training sessions either in the morning (8–9 a.m.) or evening (8–9 p.m.). Participants practiced producing two nonnative Danish vowels—[y] and [ø]—across 320 trials, guided by visual and auditory cues.

The results of the acoustic analyses were striking. Learners who trained during their nonpeak times—experiencing chronotype asynchrony—showed a greater rate of improvement than those practicing during peak alertness. These findings mirror patterns observed in other forms of implicit procedural learning, such as perceptual and visual category learning.

“Our findings suggest that strategically scheduling learning sessions during non-optimal times for implicit tasks like speech motor learning may actually accelerate progress,” van Zelst said. “This challenges traditional approaches and opens new possibilities for optimizing educational and clinical interventions.”

The study underscores the importance of understanding the role of circadian rhythms when designing learning protocols. By harnessing the power of time, educators and clinicians may unlock more efficient pathways to skill acquisition—simply by harnessing the body’s natural time schedule.