Reading aloud in clear speech reduces sentence recognition memory and recall for native and non-native talkers.

Speaking style variation plays a role in how listeners remember speech. Compared to conversational sentences, clearly spoken sentences were better recalled and identified as previously heard by native and non-native listeners. The present study investigated whether speaking style variation also plays a role in how talkers remember speech that they produce. Although distinctive forms of production (e.g., singing, speaking loudly) can enhance memory, the cognitive and articulatory efforts required to plan and produce listener-oriented hyper-articulated clear speech could detrimentally affect encoding and subsequent retrieval. Native and non-native English talkers' memories for sentences that they read aloud in clear and conversational speaking styles were assessed through a sentence recognition memory task (experiment 1; N = 90) and a recall task (experiment 2; N = 75). The results showed enhanced recognition memory and recall for sentences read aloud conversationally rather than clearly for both talker groups. In line with the "effortfulness" hypothesis, producing clear speech may increase the processing load diverting resources from memory encoding. Implications for the relationship between speech perception and production are discussed.

Face masks and speaking style affect audio-visual word recognition and memory of native and non-native speech.

Though necessary, protective mask wearing in response to the COVID-19 pandemic presents communication challenges. The present study examines how signal degradation and loss of visual information due to masks affects intelligibility and memory for native and non-native speech. We also test whether clear speech can alleviate perceptual difficulty for masked speech. One native and one non-native speaker of English recorded video clips in conversational speech without a mask and conversational and clear speech with a mask. Native English listeners watched video clips presented in quiet or mixed with competing speech. The results showed that word recognition and recall of speech produced with a mask can be as accurate as without a mask in optimal listening conditions. Masks affected non-native speech processing at easier noise levels than native speech. Clear speech with a mask significantly improved accuracy in all listening conditions. Speaking clearly, reducing noise, and using surgical masks as well as good signal amplification can help compensate for the loss of intelligibility due to background noise, lack of visual cues, physical distancing, or non-native speech. The findings have implications for communication in classrooms and hospitals where listeners interact with teachers and healthcare providers, oftentimes non-native speakers, through their protective barriers.

Clear speech improves listeners' recall.

The present study examined the effect of intelligibility-enhancing clear speech on listeners' recall. Native (n = 57) and non-native (n = 31) English listeners heard meaningful sentences produced in clear and conversational speech, and then completed a cued-recall task. Results showed that listeners recalled more words from clearly produced sentences. Sentence-level analysis revealed that listening to clear speech increased the odds of recalling whole sentences and decreased the odds of erroneous and omitted responses. This study showed that the clear speech benefit extends beyond word- and sentence-level recognition memory to include deeper linguistic encoding at the level of syntactic and semantic information.

Effects of intelligibility on within- and cross-modal sentence recognition memory for native and non-native listeners.

The goal of the study was to examine whether enhancing the clarity of the speech signal through conversational-to-clear speech modifications improves sentence recognition memory for native and non-native listeners, and if so, whether this effect would hold when the stimuli in the test phase are presented in orthographic instead of auditory form (cross-modal presentation). Sixty listeners (30 native and 30 non-native English) participated in a within-modal (i.e., audio-audio) sentence recognition memory task (Experiment I). Sixty different individuals (30 native and 30 non-native English) participated in a cross-modal (i.e., audio-textual) sentence recognition memory task (Experiment II). The results showed that listener-oriented clear speech enhanced sentence recognition memory for both listener groups regardless of whether the acoustic signal was present during the test phase (Experiment I) or absent (Experiment II). Compared to native listeners, non-native listeners had longer reaction times in the within-modal task and were overall less accurate in the cross-modal task. The results showed that more cognitive resources remained available for storing information in memory during processing of easier-to-understand clearly produced sentences. Furthermore, non-native listeners benefited from signal clarity in sentence recognition memory despite processing speech signals in a cognitively more demanding second language.