Large Area Assistive Listening Systems: Review and Recommendations

8.2.4 Procedure

To adjust to a comfortable listening level the listeners were instructed to indicate the level of the quiet, undistorted sentences that they felt they could listen to for a very long time. Listeners were instructed to judge the quality of the sentences by selecting one of the following ratings.

1. Excellent

2. Good(I would purchase a ticket for a show

3. Marginal (I may or may not purchase a ticket for a show)

4. Unacceptable (I would not purchase a ticket for a show)

Listeners were tested in five blocks of trials for each of the listening conditions. Sentences were always presented in female/male question/reply pairs. Pairs for each level of distortion were presented six times. The protocol consisted of a pretest phase where sentence pairs were were presented in two orders from greatest degradation to quiet and quiet to greatest degradation. Following the pretest phase, the remaining four pairs of sentences for each level of distortion were presented in random order. The final result for each listener represents an average of the four rating responses for each subcondition recorded following the pretest phase.