Something like this would be anxiety inducing for most people, I bet. That'd be an excellent experiment, track heart rate, EEG, and performance on a range of cognitive tasks with 2 minute long breaks between each tasks, one group exposed to the irregular ticking, another exposed to regular ticking, another with silence, and one last one with pleasant white noise.
It's just the right amount of "did that clock just skip a beat? Nah must just be my imagination".