Why this study? Valtteri Hongisto stated that there are no previous studies which have investigated the effects of office noise on the stress hormone levels (concentrations in the body) using the most precise and real-time method: i.e. blood sampling. Also a questionnaire was used to evaluate the effect. 100 person participated in the study and Valteris team involved 16 people as it was a large effort to perform all tasks. An ethical approval was also neccessary from the University hospital.
The purpose of their study was to investigate how unnecessary speech (speech that has nothing to do with your current task) at normal conversation level (65 dB L Aeq) affects humans on a holistic level, while they are working, by using an exceptionally broad range of human outcomes:
- Psychological effects (distraction & workload)
- Cognitive effects (work performance)
- Physiological effects (stress)
Stress hormone levels, results
- Psychological effects of sound conditions: Adverse effects were much larger in Speech than in Silence for annoyance and workload
- Performance effects of sound conditions: Accuracy was worse in Speech than in Silence
- Physiological effects of sound conditions: Cortisol concentration in blood plasma was higher in Speech than in Silence condition. And heart rate variability increased with time in Speech, but not in Silence.
Valtteri concluded that unnecessary speech at 65 dB L Aeq caused the following adverse effects related to health and well-being during working: Increased annoyance, increased workload, reduced performance, and increased physiological stress. These effects were found already after 50 min exposure to speech.
Thank you for a very interesting presentation!
The local newspaper also did an interview with Valtteri, watch and read it here!