The authors' aim was to study noise-related problems in personnel at Swedish daycare centers. The authors' study comprised staff (N = 81) who completed a questionnaire (noise, illumination, indoor climate, hearing problems) at five daycare centers with noise problems. After basic and activity sound measurements, absorbers were attached to the ceilings and to two adjacent walls in the playing and dining rooms. Thereafter, basic and activity sound measures were repeated and the questionnaire was also repeated six months later. The acoustical treatment reduced the sound pressure levels by 2 to 6 dB in the playing rooms and by 0 to 3 dB in the dining rooms. The reverberation time was reduced by 20% to 50%. After the treatment the perceived noise disturbance level decreased slightly but not significantly and the proportion of the staff who often or very often planned the daily activities to reduce the noise level had decreased from about 39% to 25%. Similarly, the percentage that often or very often had a need for silence after work had decreased from 42% to 37%. (author abstract)