The relationship between intelligibility and comprehensibility in second language speech

This study examined the relationship between intelligibility and comprehensibility in second language speech. Four extended speech samples from 50 speakers spanning a wide range of proficiency were drawn from archived test data. These samples were listened to by 570 English users, who provided comprehensibility ratings and transcriptions to measure intelligibility. The relationship between intelligibility and comprehensibility was strong (r = .81, ⍴ = .88) and nonlinear. A segmented regression model suggested a breakpoint for intelligibility scores (transcription accuracy) at 64%, below which speakers were perceived as uniformly hard to understand and above which increased intelligibility was strongly associated with higher comprehensibility.