Potentials of a matrixed word test for assessing speech reception in rooms with reverberation and noise

The use of listening tests based on list of sentences is well established in audiology for evaluating hearing loss. The testing material is usually presented diotically under simplified listening conditions (anechoically, in quiet or with stationary noise). In this work the efficacy of a matrixed word test in the Italian language was assessed for the description of the speech reception performance in complex noisy and reverberant conditions. The speech material was chosen phonetically balanced; the test sentences were composed by a carrier phrase followed by a sequence of syntactically uncorrelated meaningful target words. Tests were proposed in a closed-set format to 18 native Italian speakers, reporting normal hearing. Speech–intelligibility scores and response times were measured under noise and reverberation, and in a quiet control condition which served to set the performance baseline. In the former condition a speech-shaped steady-state noise was selected as masker and SNR and reverberation were combined to create a listening scenario with an STI=0.48. The tests were administered in a silent room via a three-dimensional audio rendering system. The length of the sequences was varied from two up to six word items, as to select the length able to provide the best performance in resolving the listening conditions. The results show that optimal results are obtained by the four words test. The outcomes were additionally compared with existing speech recognition tests already available in the Italian language (DRT and matrix sentence test).