A Listenability Index Consisting of Subjective Judgment and Objective Evaluation

Although the use of listening materials on the Internet has several advantages for learning/teaching English as a foreign language, it causes a drawback that teachers need to examine listenability in preparing materials for their learners to avoid mismatching with learners' proficiency, which is a time and effort consuming task. This is because the ease of listening materials (henceforth, listenability) is uncontrolled, unlike commercially available listening materials. Then,. An automatic listenability measurement method reduces teachers' task by classifying listening materials according to the listenability levels. Previous methods using natural language processing techniques used listenability indices determined by learners' subjective judgments on listenability (hereafter, SBJ) or objective evaluation results in terms of learners' transcription accuracy (hereafter, OBJ). This study proposes a third type of listenability index by combining SBJ and OBJ, and reports experimental results reading the reliability and validity of the proposed complex listenability index. The results demonstrated higher reliability and validity than simple listenability indices, and high accuracy of the listenability measurement.