Professional voice use in high school classrooms: relationships between classroom acoustics and voice parameters of teachers at the beginning and at the end of a school year

Objective: To accurately determine changes in the voice use of teachers along a school year. Furthermore, the relationship between vocal parameters, classroom acoustics and noise is statistically investigated. Methods: 37 teachers from two high schools in Torino (Italy) participated in this study at the beginning of a school year. 32 of them took part in the study also at the end of the same school year. In each period teachers were monitored repeatedly, adopting the same procedure, using the Voice Care device, which consists in a contact microphone to be placed at the jugular notch connected to a data logger. Vocal acquisitions contained information on the voice-use for entire lessons, from which plenary lesson monitorings were extracted since they require the highest phonation load. Each teacher performed an interview before each monitoring to obtain a conversational speech level. Sound pressure level (SPL), fundamental frequency (F0) and phonation time percentage (Dt%) were evaluated to characterize the vocal behavior and fatigue under different lessons and periods. A perceptual assessment of voice was also performed to investigate changes in the vocal health of teachers along a school year. Results: Voice parameters were analyzed in relation with the reverberation and noise conditions in which they were measured. Overall, it appeared that teachers adjust their voice significantly with the reverberation time both at the beginning and at the end of the school year, as well as with noise. Moreover, teachers who worked in worst acoustic conditions showed an increase in SPL at the end of the school year. Conclusions: Classroom acoustics and noise significantly influence teachers’ voice throughout an entire school year. To prevent from voice-related pathologies it is therefore important to solve acoustical issues as well as to determine a prevention program that easily allows monitoring the voice status of professionals in their workspaces

A longitudinal study on vocal behavior of teachers in classrooms and relationships with classroom acoustics

The objective of the longitudinal study presented in this work is twofold: to determine changes in the voice use of teachers along a school year and to study the relationships between voice and classroom acoustics parameters, which account for the background noise level during the teaching hours too. Thirty-one teachers from two secondary schools in Torino (Italy) were involved at the beginning of a school year and twenty-two of them participated in the monitoring campaign also at the end of the same school year too. Teachers adjust their voice significantly with noise and reverberation, both at the beginning and at the end of a school year. Moreover, teachers who worked in worst classroom acoustic conditions showed higher voice sound pressure levels at the end of the school year. Finally, a good predictive model to estimate the sound pressure level in front of the speaker’s mouth from the background noise level and the reverberation time was found

One-year longitudinal study on teachers’ voice parameters in secondary-school classrooms: relationships with voice quality assessed by perceptual analysis and voice objective measures

This longitudinal work explores the relationships between three analyses used for assessing teachers’ voice use: the voice monitoring during lessons that describes the teachers’ Vocal Behavior (VB), the perceptual assessment of voice by speech-language pathologists and the estimation of objective parameters from vocalizations to define teachers’ Vocal Performance (VP). About thirty Italian teachers from secondary schools were involved at the beginning and at the end of a school year. In each period, teachers’ vocal activity was monitored using the Voice Care device, which acquires the voice signal through a contact microphone fixed at the neck to estimate sound pressure level, fundamental frequency and voicing time percentage. Once in each period, two speech-language pathologists performed a perceptual assessment of teachers’ voice using the GIRBAS-scale. On that occasion, teachers vocalized a sustained vowel standing in front of a sound level meter in a quiet room. Jitter, Shimmer and other parameters were extracted using Praat, while a new metric of Cepstral-Peak-Prominance-Smoothed was estimated with a MATLAB script. Several relationships between the outcomes of each analysis were investigated, e.g. statistical differences between the dimension “G” from GIRBAS-scale and objective measures for VB and VP, and correlations between objective measures and perceptual ratings were assessed

Il controllo del rumore tramite un semaforo acustico intelligente che aiuta a regolare la propria emissione vocale: S&N-S Light

Gli studi attuali confermano che il rumore sia fra le principali cause del peggioramento della qualità della vita nelle aree urbane e negli ambienti densamente occupati. Nelle aree urbane le principali fonti di inquinamento acustico comprendono, oltre al traffico stradale, il rumore legato alla vita notturna. Sono diverse le azioni intraprese dalle amministrazioni comunali per affrontare e risolvere il fenomeno, ma non sembrano ancora sufficienti ad arginare un problema sempre più diffuso. Negli ambienti densamente occupati, quali scuole, locali di ristorazione ecc., oltre ai rumori generati dagli impianti e di impatto, una delle principali sorgenti di inquinamento acustico è il livello della voce delle persone. Studi che valutano la percezione dell'acustica negli ambienti scolastici da parte di studenti e docenti hanno individuato proprio nella voce degli studenti che parlano all'interno dell'aula il disturbo principale. Inoltre, numerosi monitoraggi del rumore nelle scuole hanno fatto emergere un'esposizione elevata specialmente nelle scuole materne ed elementari. La conseguenza principale dell'esposizione a livelli di rumore eccessivi è già stata dimostrata essere l'insorgenza di danni uditivi e di laringopatie nel corpo docente, oltre ad essere causa di difficoltà di apprendimento e perdita di attenzione negli alunni. Risulta quindi molto importante sviluppare strumenti e strategie per sensibilizzare gli utenti circa gli effetti della loro emissione vocale sulle condizioni acustiche dell'ambiente. Per questo è stato sviluppato e brevettato un semaforo acustico intelligente, lo Speech & Noise Stop Light (S&N-S light), che misura i livelli di rumore presenti in ambienti densamente occupati e che suggerisce un autocontrollo del livello di voce basandosi sulla segnalazione luminosa dei semafori stradali. L'innovazione del sistema è quella di essere uno strumento che non reagisce ai rumori istantanei e che si adatta automaticamente alle condizioni generali presenti nell'ambiente. Ad ora sono stati realizzati sei prototipi di S&N-S Light, impiegati in tre campagne di misura che hanno coinvolto le aule di una scuola superiore, il dehor di un locale notturno in un contesto urbano e le sale di un locale di ristorazione. L'obiettivo di queste campagne di monitoraggio è stato orientato a sensibilizzare l'autoregolazione del livello della voce degli utenti in presenza del dispositivo. Dai risultati è emerso un abbassamento dei livelli di rumore, in particolare quando l'utilizzo del semaforo è affiancato da una campagna informativa di sensibilizzazione tramite la diretta comunicazione verbal

A one-school year longitudinal study of secondary school teachers' voice parameters and the influence of classroom acoustics

Recent literature reports that a large percentage of teachers complain that teaching has an adverse effect on their voice status. Thus, more needs to be done to study their vocal behavior. The objective of this longitudinal study was twofold: to determine changes in the voice use of teachers over a school year, and to study the relationships between voice use and classroom acoustic parameters. Thirty-one teachers from two secondary schools in Turin (Italy) were involved at the beginning of the 2014-2015 school year, and 22 of them also participated at the end of the same school year. The results show that teachers adjust their voices with noise and reverberation. A minimum value of the sound pressure level of voice (SPL) was found at a mid-frequency reverberation time of 0.8 s in both periods. Moreover, the teachers who worked in the worst classroom acoustic conditions showed an increase of 2.3 dB in the mean SPL and a decrease of 10% in the voicing time percentage at the end of the school year. A predictive model that can be used to estimate the mean SPL from the background noise level and the reverberation time, based on collected data, is here proposed

Effect of outdoor noise and façade sound insulation on indoor acoustic environment of Italian schools

The paper deals with the effect of outdoor noise mainly due to traffic and façade sound insulation on indoor noise level and speech intelligibility in classrooms. Results refer to the complete building stock of the Italian school buildings based on a census of the Italian Ministry of Education. The selected school sample consists of more than one hundred Italian schools of all levels (from nursery to upper secondary school) located in three Italian regions, built in different time periods and with different building techniques. The selected sample is representative of typical Italian schools. The façade sound insulation and the reverberation time of each school have been measured. The average outdoor noise level of about half the investigated schools has been measured and, for each school, the age of the building and the main characteristics of the façade have been listed (kind of glass, kind of ventilation, windows size, etc.). Based on these data, the correlations between both the main characteristics of the façades and the year of construction and the façade sound insulation have been investigated. Moreover, the influence of the noise coming from outdoor on the indoor noise level, speech intelligibility and speech to noise ratio have been analysed with reference to the situations both before and after the works carried out to improve the acoustic performances of façades. Results show that the indoor sound pressure level due to traffic noise is considerably reduced after the improvement of the façade acoustic insulation, while further treatments to indoor surfaces should be necessary to reduce internal reverberation time and to improve speech intelligibility

Long-term monitoring campaigns in primary school: the effects of noise monitoring system with lighting feedback on noise levels generated by pupils in classrooms

Noise levels generated by pupils talking and moving greatly affect teaching and learning process in primary schools. Teachers tend to raise their voice level in order to improve intelligibility under noisy learning environment, negatively affecting their vocal health. More efforts need to be done to study an educational method to reduce chatting noise directly involving occupants’ behavior. This study aimed to evaluate the effects on noise reduction generated by active involvement of the pupils in lowering their voice volume when advised by a noise monitoring system with lighting feedback, namely SEM (Speech and Sound SEMaphore). Monitoring campaigns were carried out over 3 scholastic years in 13 primary school classes (4÷5 for year) in Turin (Italy). The background noise level, L90, was measured in two conditions with the lighting feedback of SEM switched off and on. The comparison between these conditions was analyzed for the overall classes for a total of 550 cases. The results showed an improvement in 51% of cases in terms of decrease of L90 mean values when SEM lighting feedback was on, where the average decrease of the L90 mean values was of about 3.0, 2.7 and 3.3 dB in first, second and third scholastic year, respectively