Are they really listening? Watch their blinks

Your eyes may reveal when your brain is working overtime. Researchers found that people blink less when trying to understand speech in noisy environments, especially during the most important moments. The effect stayed the same in bright or dark rooms, showing it’s driven by mental effort, not light. Blinking, it turns out, is a quiet marker of focused listening.

source https://www.sciencedaily.com/releases/2025/12/251222043239.htm