8–12 Sept 2026
Europe/Vienna timezone

Spatial decay of speech has an important role in open and enclosed learning spaces

FA2026/578
9 Sept 2026, 11:00
20m
Saal 12B (Messe Congress Graz)

Saal 12B

Messe Congress Graz

Speaker

Jukka Keränen (Turku University of Applied Sciences)

Description

Open learning spaces, OLSs, which enable teaching more than one group of students at a time, have become increasingly popular. Enclosed learning space, ELS, (conventional classroom) is still the most popular learning space type. Our purpose was to report on the room acoustic properties of both learning space types using measurements according to ISO 3382-3. This method was justified since Finnish regulations set distance-dependent target values for STI in OLS and distance-independent target values for ELSs. Measurements concerned speech transmission index, STI, background noise level, LAeq, and reverberation time, T. Variation in results in both OLSs and ELSs was rather large. In OLSs STI was 0.47–0.91, LAeq 29–44 dB, and T 0.44–0.72 s. In ELSs STI was 0.64–0.83, LAeq 25–47 dB, and T 0.34–0.82 s. The results of LAeq and T in OLSs and ELSs were surprisingly similar. STI values were within target values in most ELSs, unlike in most OLSs, where the target values were violated at longer distances, because STI did not decrease as steeply as required. Our finding suggests that measurement of spatial decay is justified in both learning space types because it reveals how STI behaves at different distances from the speaker.

Authors

Jukka Keränen (Turku University of Applied Sciences) Valtteri Hongisto (Turku University of Applied Sciences)

Presentation materials