Introduction: Human performance is influenced by several job-related factors and workplace conditions, including occupational noise. This influence can occur at sound pressure levels lower than the ones that cause physiological damage, such as hearing loss, being mediated by the noise characteristics. However, studies concerning this issue are still scarce. Study.
Aim: The aim of this study was to investigate the effects of three noise conditions on attention and short-term memory: standard condition (C1), environmental noise without alarm sounds (C2), and environmental noise with alarm sounds (C3).
Materials and methods: First, noise levels were measured during a normal workweek in a fast food establishment. Second, an experiment was designed to simulate the noise normally prevailing in the workplace. The noise levels were fixed at 45 ± 0.3 dB(A) (C1), 60 ± 0.4 dB(A) (C2), and 68 ± 0.4 dB(A) (C3). The influence of noise on participants' attention and short-term memory was assessed with the following test battery: serial recall, response inhibition, and Stroop interference. Because annoyance, stress, and discomfort perceptions during the tests can influence results, visual analog scales to assess these variables were applied in the end of each trial. Fifteen undergraduate students were included in this pilot study (20-23 years; M = 21.6; SD = 0.8; all female).
Results: The results demonstrated that participants' performance during the tests was lower in C3, that is, the number of errors was higher and the reaction time longer. Participants also experienced higher levels of discomfort, stress, and annoyance perceptions in this condition. However, task performance was not found to be influenced by these perceptions.
Conclusion: This study provided important insights about the different noise conditions that workers are exposed in a fast food restaurant, and how they influence participants' performance. Further research should involve workers, exploring how these conditions are implicated in their performance in the field.
Keywords: Annoyance; occupational noise; performance; short-term memory task; stress.