This study was designed to determine the nature and occurrence of hesitation phenomena in spontaneous speech of native and non-native speakers, and to determine whether and to what extent the hesitation phenomena normal in spontaneous speech pose perception problems for non-native speakers. A quantitative analysis reveals that hesitation phenomena are ubiquitous in both native and non-native speech production. A qualitative analysis based on a content-processing classification framework reveals the function of hesitations. Hesitations act as overt traces of prospective and retrospective speech-processing tasks which function to forestall errors, and to permit detection and repair of errors once they are committed. Hesitations are quality control devices; native and non-native speakers are highly successful utilizing them to forestall errors. However, hesitation phenomena clearly pose perception problems for non-native speakers who show little evidence of recognizing them as such. Like native speakers, non-native speakers produce hesitation phenomena. Unlike native speakers, who edit and filter out the hesitations they hear, non-native speakers attempt to assign meaning to speakers' faulty output or to parenthetical remarks. Hesitations are unpredictable in their frequency or occurrence; failure to provide training in these oral discourse features of connected speech may result in non-native speakers whose speech production vastly outstrips their perception.
The Lombard intelligibility benefit of native and non-native speech for native and non-native listeners
