Background Healthcare professionals working in emergency medicine are often exposed to noisy environments. We determined if there is any difference in cognitive task performance required for clinical decision-making of healthcare professionals in a quiet compared with noisy environment and to assess the subjective experience of participants with regard to performance in a noisy environment.

Methods This was a prospective cross-over study conducted at three academic hospitals in Johannesburg, South Africa. 41 doctors involved in the emergency management of patients were administered six matched and prevalidated medical questions over a 30-min period. Each doctor completed half of the questions with exposure to ambient noise (range 40–52 dB(A)) and the other half with exposure to pre-recorded background emergency department noise at 80–85 dB(A). The questions were completed in alternating quiet and noise: half of the physicians answered the odd questions in noise and half answered even numbered questions in noise. Each question was scored out of 10 and the time taken to complete each question was recorded.

Results Overall median test scores in quiet and noise were 18.5/30 and 20/30 (p=0.2), respectively; time for test completion was longer in quiet (836 s in quiet and 819 s in noise (p=0.006)). While there was no statistically significant difference in task performance, 65% of the doctors found the noise distracting with 88% experiencing varying degrees of stress.

Conclusions Performance of mental tasks is maintained during noise exposure but noise exposure is associated with significant degrees of self-reported distress.