Exploring the Levenshtein Distance as a measure of intelligibility of foreign accents
2022-04-12, 17:00–17:30 (Europe/Vienna), Room 1


English, as the current lingua franca, is spoken by millions of people for whom it is not their native language. All these speakers present a wide range of accent varieties which are, on the most part, influenced by their L1.

Given this situation, being intelligible has become crucial in English as a Lingua Franca (ELF) communication (Jenkins 2000; Levis 2005). At the beginning of the 21st century, Jenkins (2000) concluded that most of the misunderstandings in ELF spoken interactions could be linked to deviations in pronunciation. As a result, she proposed a list of pronunciation features which non-native speakers of English should accurately produce in order to be intelligible. This list, which Jenkins called the Lingua Franca Core (LFC), includes "most consonant sounds, appropriate consonant cluster simplification, vowel length distinctions and nuclear stress" (Jenkins, 2000, p. 132).

'Intelligibility', as understood by Smith & Nelson (1985, 334) is related to the "recognition of words", thus focusing on the pronunciation of sounds, in contrast with 'comprehensibility' (related to the meaning of words) and 'interpretability' (linked to the pragmatics of the utterance). There are several methods used to measure speech intelligibility, such as orthographic transcriptions of spoken stimuli (Munro, Derwing, and Morton 2006; Osimk 2009), cloze tests (Smith and Nelson 2006) or translations of speech fragments into the listeners’ L1 (Gooskens, Heeringa, and Beijering 2008). However, all these methods only rely on the subjective perceptions of participants.

As a result, objective methods, such as dialectometry, are deemed necessary to measure the intelligibility of foreign-accented speech. In this sense, dialectometric studies have generally described varieties of single languages (Wieling 2012) or studied the intelligibility of related languages (Beijering, Gooskens, and Heeringa 2008; Gooskens, Heeringa, and Beijering 2008), while dialectometric analyses of foreign-accented speech remain scarce and centered in the study of foreign-accentedness (Bloem et al. 2016; Wieling et al. 2014), rather than speech intelligibility.

The present research aims at exploring the use of the ELF-based Levenshtein Distance (ELF-LD) (Jurado-Bravo and Kristiansen 2019) to measure the intelligibility of Spanish-accented English speech. 215 people from different L1 backgrounds completed an intelligibility test in which they orthographically transcribed several speech stimuli uttered by 15 female Spanish speakers of English. The number of correctly transcribed words was transformed into an intelligibility score and correlated with the ELF-LD calculated for each speaker.

Results show there is a statistically significant moderate relationship between the ELF-LD and the subjective intelligibility scores, concluding that the ELF-LD may be a good method to objectively measure speech intelligibility. A closer analysis of the subjective data shows that some pronunciation deviations which were expected to be intelligibility-threatening (Jenkins, 2000) are not so, which could explain why the correlation, even though significant, is not as strong as expected.


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