title: Subjective and objective speech intelligibility investigations in primary school classrooms.
abstract: This work concerns speech intelligibility tests and measurements in three primary schools in Italy, one of which was conducted before and after an acoustical treatment. Speech intelligibility scores (IS) with different reverberation times (RT) and types of noise were obtained using diagnostic rhyme tests on 983 pupils from grades 2-5 (nominally 7-10 year olds), and these scores were then correlated with the Speech Transmission Index (STI). The grade 2 pupils understood fewer words in the lower STI range than the pupils in the higher grades, whereas an IS of ~97% was achieved by all the grades with a STI of 0.9. In the presence of traffic noise, which resulted the most interfering noise, a decrease in RT from 1.6 to 0.4 s determined an IS increase on equal A-weighted speech-to-noise level difference, S/N(A), which varied from 13% to 6%, over the S/N(A) range of -15 to +6 dB, respectively. In the case of babble noise, whose source was located in the middle of the classroom, the same decrease in reverberation time leads to a negligible variation in IS over a similar S/N(A) range.
authors.affiliation: Politecnico di Torino, Department of Energetics, Corso Duca degli Abruzzi 24, 10129 Torino, Italy. arianna.astolfi@polito.it
authors.forename: Arianna
authors.initials: A
authors.lastname: Astolfi
authors.forename: Pasquale
authors.initials: P
authors.lastname: Bottalico
authors.forename: Giulio
authors.initials: G
authors.lastname: Barbato
mesh_terms: D000162:Acoustics; D002648:Child; D003198:Computer Simulation; D004779:Environment Design; D006801:Humans; D007558:Italy; D009622:Noise; D010470:Perceptual Masking / Q000502:physiology; D015203:Reproducibility of Results; D012574:Schools; D059629:Signal-To-Noise Ratio; D013018:Sound Spectrography; D013063:Speech Discrimination Tests; D013065:Speech Intelligibility / Q000502:physiology*