Perceived listener effort (PLE) has been defined as the perceived “amount of mental exertion required to attend to, and understand, an auditory system” (McGarrigle et al., 2014). PLE may be affected by multiple characteristics of the speech signal, including sentence length and intelligibility. Previous qualitative data indicates that listeners are also sensitive to speaking rate. This experiment measured the effect of speech rate on PLE for speech produced with a range of intelligibility. Eleven listeners with normal hearing (HINT), working memory (WAIS-IV), and receptive vocabulary (PPVT) transcribed and rated their PLE for the 144 low-context sentences produced with a monotone electrolarynx (EL) set at 75 Hz. Speech rate (syllables per second) was measured from onset of the first word to offset of the last word. Multiple regression analysis indicated that intelligibility and speech rate accounted for a significant amount of variance in PLE scores, R2=.70, F(2,142) = 168.803, p < .001, R2adj = .70. Intelligibility had a unique negative effect on PLE ratings (b = -6.45, SE = .35), t(142) = -18.37, p < .001, sr2 = .70; however, rate was not uniquely predictive (p >.05). Future research should examine the associations among radiated noise, articulatory characteristics and PLE for EL speech.
Nagle, Kathleen F. (2015). Effect of intelligibility and speech rate on perceived listener effort. The Journal of the Acoustical Society of America, 137, 2433-2433. DOI: 10.1121/1.4920878 available online at