The popularity of open-plan offices has been on the rise recently and expanded to all sectors of working life. While moving to open-plan offices brings savings to companies, open-plan offices have been connected with various different negative consequences, such as noise. Noise has been found to be a central cause of dissatisfaction towards working in an open-plan office and lead to subsequent negative outcomes, such as decreased self-perceived health and weakened cognitive performance. There- fore, it is important to study the ways and technologies that could possibly mitigate the negative effects of noise on work well-being and work performance. This explorative study investigates both the objec-tively measured and subjectively perceived effects of adopting noise cancellation earplugs by open- plan office workers in a software company. In physiological measurements, the usage of noise cancellation earplugs was not found to affect work stress or work strain nor affect the stress-recovery balance. In psychological measurements, the perceived effects of using the earplugs on work well-being and work performance were small but rather negative than positive. This could be due to negative perceived comfort and usage experiences with the earplugs. Besides open-plan offices, the findings are mostly generalizable to other office settings as well.