Rank ordering of class grades and noise interference by means of listening efficiency in primary schools

The concept and measurement of listening efficiency was proposed recently as an improvement of the current speech intelligibility metric, and proved to be convenient specifically with regard to the performance of different age groups. The present work has the aim of generalizing the former results by applying the methodology to real classrooms, with three types of noises (activity, traffic and tapping). This study involves 741 pupils aged from 6 to 10 years (I to V grade) in 6 primary schools. WIPI tests were used with I and II grade students whereas DRT tests were accomplished with III, IV and V grade ones. A novel wireless system designed to collect word choices and response times was employed, and the listening efficiency was obtained. By means of tailored statistical testing, known as stochastic ordering by means of permutation tests, it was possible to elaborate a detailed rank ordering of the class abilities and of the peculiar interference of the noise types on pupils’ performance. Firstly it was shown how the rank ordering becomes more and more clear with the improvement of the listening conditions. Then an ordering according to the classes was achieved for both WIPI and DRT groups. The ordering with the noise type was quite effective for the DRT tests (III, IV and V grade) whereas for the younger pupils (WIPI tests, I and II grades) an unambiguous ordering was not possible.