Blinking is something people do automatically, much like breathing, without giving it much thought. While most scientific research on blinking has focused on eyesight, a new study from Concordia University explores a different connection. The research looks at how blinking relates to cognitive processes, including how the brain filters out background noise so we can focus on speech in busy environments.

The findings were published in the journal Trends in Hearing. In the paper, researchers outline two experiments designed to observe how blinking behavior changes when people are exposed to different listening conditions.

Fewer Blinks Signal Greater Mental Effort

The researchers discovered that people tend to blink less when they are working harder to understand speech in noisy settings. This reduction in blinking appears to reflect the mental effort involved in listening closely during everyday conversations. Importantly, the pattern stayed the same regardless of lighting conditions -- participants blinked at similar rates whether the room was bright, dim, or dark.

"We wanted to know if blinking was impacted by environmental factors and how it related to executive function," says lead author Pénélope Coupal, an Honours student at the Laboratory for Hearing and Cognition. "For instance, is there a strategic timing of a person's blinks so they would not miss out on what is being said?"

The results showed that blinking does appear to be timed in a purposeful way.

"We don't just blink randomly," says Coupal. "In fact, we blink systematically less when salient information is presented."

Measuring Blinks During Challenging Listening Tasks

The study included nearly 50 adult participants. Each person sat in a soundproof room and focused on a fixed cross displayed on a screen. They listened to short spoken sentences through headphones while the level of background noise changed. The signal-to-noise ratio (SNR) ranged from very quiet to highly distracting.

Participants wore eye-tracking glasses that captured every blink and recorded exactly when each blink occurred. Researchers divided each listening session into three phases: before the sentence played, while it was playing, and immediately afterward.

Blink rates dropped most noticeably during the sentences themselves, compared to the moments before and after. The decrease was strongest when background noise was loudest and speech was hardest to understand.

Lighting Does Not Explain the Effect

In a second experiment, the team tested blinking behavior again while changing the lighting conditions. Participants completed the listening tasks in dark, medium, and brightly lit rooms, across different SNR levels. The same blink suppression pattern appeared each time.