A Voice Ergonomic Study in Icelandic Preschools: What Causes the Activity Noise and How to Attenuate It

Preschool sound environments are predominantly shaped by activity noise generated by voices, object impacts, furniture movement, and daily transitions. Although Icelandic preschools typically comply with reverberation standards, staff frequently report excessive noise, high listening effort, and vocal strain.

This mixed-method pre-post study examined the sources and reducibility of activity noise in three Icelandic preschools using a voice-ergonomic framework. Data included objective noise measurements at child ear height, structured observations, and teacher questionnaires. The intervention combined voice-ergonomic and noise-awareness education for staff and children with targeted organisational, behavioural, and material adjustments.

Baseline mapping identified children's voices and object impacts as the dominant noise sources. Following the intervention, measured noise decreased significantly, with mean L_Aeq reduced by 1.9 dB (p = 0.013), corresponding to an approximate 35% reduction in acoustic energy. The largest improvements occurred in high-noise areas such as dining rooms. Despite these improvements, voice symptoms and stress remained prevalent, suggesting that substantial vocal demands persisted despite the intervention and that increased voice awareness may also have influenced symptom reporting.

The findings indicate that activity noise represents the primary acoustic challenge in preschool environments and highlight children's particularly high local noise exposure. The results support the need for more child-centred acoustic standards that extend beyond reverberation time alone and place greater emphasis on favourable signal-to-noise conditions, listening effort, speech communication, and vocal health in preschool environments.