Overview

The R lists were developed to evaluate electronic communication systems by Professors J. P. Egan and S. S. Stevens during the 1940s at the Psycho-Acoustic Laboratory, Harvard University. Lists of sentences, words, or syllables can be used to measure the intelligibility of speech by determining the percentage correctly recognized by a listener (called an articulation test). For example, the lists can be used by talkers and normal-hearing listeners to evaluate the effect of ambient noise, long-delayed reflections and echoes, and other room acoustics faults on listening conditions in churches, small auditoriums, classrooms, and the like. The talker should stand at the lectern or podium and read from the lists in a normal speaking voice. Because the test is designed to assess hearing, not memory, the lists should be read in altered sequence when several locations are to be evaluated in the same room. In addition, test results should be scored for correct hearing, not spelling. Convert score of percent understood to an articulation index (Al) by using the graph on page 400. For very good speech listening conditions in rooms, the Al should be greater than 0.7.

Egan's R List 1