It is well documented that the interference of noise in the classroom puts younger pupils at a disadvantage for speech perception tasks. Nevertheless, the dependence of this phenomenon on the type of noise, and the way it is realized for each class by a specific combination of intelligibility and effort have not been fully investigated. Following on a previous laboratory study on "listening efficiency," which stems from a combination of accuracy and latency measures, this work tackles the problems above to better understand the basic mechanisms governing the speech perception performance of pupils in noisy classrooms. Listening tests were conducted in real classrooms for a relevant number of students, and tests in quiet were also developed. The statistical analysis is based on stochastic ordering and is able to clarify the behavior of the classes and the different impacts of noises on performance. It is found that the joint babble and activity noise has the worst effect on performance whereas tapping and external traffic noises are less disruptive.

In order to obtain an effective speech communication in rooms it is advisable, besides reaching the full intelligibility of words, to minimize the effort paid by the listener in the recognition of the speech material. This twofold requirement is not easily described by the current room acoustic indicators, which are mainly concerned either with a subjective rating by means of word recognition scores or with using listeners' impressions of reported listening difficulties. In this work, the problem is tackled by introducing the concept of "listening efficiency," which is defined as a combination of the accuracy of intelligibility and of the effort spent on achieving this goal. This indicator is here developed, and an application of the former and of the "listening efficiency" is presented in the field of classroom acoustics. Listening tests with pupils and adults were performed and the subsequent statistical analyses indicated several interesting findings. In particular, listening efficiency is able to clearly discriminate between equal intelligibility scores obtained under different acoustical conditions, permitting room acoustics to be tailored for specific groups, such as children.

A good agreement has been found between the SRTs and slope and those of other matrix tests. Since sentences are difficult to memorize, the Italian matrix test is suitable for repeated measurements.

The present study aimed to investigate the effects of type of noise, age, and gender on children’s speech intelligibility (SI) and sentence comprehension (SC). The experiment was conducted with 171 children between 11 and 13 years old in ecologically-valid conditions (collective presentation in real, reverberating classrooms). Two standardized tests were used to assess SI and SC. The two tasks were presented in three listening conditions: quiet; traffic noise; and classroom noise (non-intelligible noise with the same spectrum and temporal envelope of speech, plus typical classroom sound events). Both task performance accuracy and listening effort were considered in the analyses, the latter tracked by recording the response time (RT) using a single-task paradigm. Classroom noise was found to have the worst effect on both tasks (worsening task performance accuracy and slowing RTs), due to its spectro-temporal characteristics. A developmental effect was seen in the range of ages (11–13 years), which depended on the task and listening condition. Gender effects were also seen in both tasks, girls being more accurate and quicker to respond in most listening conditions. A significant interaction emerged between type of noise, age and task, indicating that classroom noise had a greater impact on RTs for SI than for SC. Overall, these results indicate that, for 11- to 13-year-old children, performance in SI and SC tasks is influenced by aspects relating to both the sound environment and the listener (age, gender). The presence of significant interactions between these factors and the type of task suggests that the acoustic conditions that guarantee optimal SI might not be equally adequate for SC. Our findings have implications for the development of standard requirements for the acoustic design of classrooms.

Pupils inside primary school classrooms can be exposed to extraneous noise, impairing their performance in the speech reception process. The different noises show a peculiar impact, depending on their level, spectral content and temporal fine structure. In order to understand how the disturbance is built up over time, in this work a large data set was analyzed, detailing the changes of pupils' performance as the lesson progresses from the start to the end. Several types of noise are considered (traffic, tapping and activity noise) and the analysis concerns III to V graders of the Italian primary school (8 to 10 year old pupils). By using as indicators the intelligibility scores, the response time and their ratio, the so-called "listening efficiency," several findings are achieved. Pupils respond differently to each noise during the course of the lesson. In the better listening conditions, the performance in the speech reception worsens under traffic and babble noise whereas an opposite trend is found under tapping noise. On the contrary adaptation is observed in the worse listening conditions for the traffic noise alone. Moreover, indications are achieved that the age proficiency may affect differently babble noise compared to traffic and tapping noise.