Degree of Language Experience Modulates Visual Attention to Visible Speech and Iconic Gestures During Clear and Degraded Speech Comprehension

Mouth and facial informativeness norms for 2276 English words

Mouth and facial movements are part and parcel of face-to-face communication. The primary way of assessing their role in speech perception has been by manipulating their presence (e.g., by blurring the area of a speaker's lips) or by looking at how informative different mouth patterns are for the corresponding phonemes (or visemes; e.g., /b/ is visually more salient than /g/). However, moving beyond informativeness of single phonemes is challenging due to coarticulation and language variations (to name just a few factors). Here, we present mouth and facial informativeness (MaFI) for words, i.e., how visually informative words are based on their corresponding mouth and facial movements. MaFI was quantified for 2276 English words, varying in length, frequency, and age of acquisition, using phonological distance between a word and participants' speechreading guesses. The results showed that MaFI norms capture well the dynamic nature of mouth and facial movements per word, with words containing phonemes with roundness and frontness features, as well as visemes characterized by lower lip tuck, lip rounding, and lip closure being visually more informative. We also showed that the more of these features there are in a word, the more informative it is based on mouth and facial movements. Finally, we demonstrated that the MaFI norms generalize across different variants of English language. The norms are freely accessible via Open Science Framework ( https://osf.io/mna8j/ ) and can benefit any language researcher using audiovisual stimuli (e.g., to control for the effect of speech-linked mouth and facial movements).

The contribution of eye gaze and movement kinematics to the expression and identification of social intention in object-directed motor actions

The intention to include another person in an interaction (i.e., social intention) is known to influence the spatio-temporal characteristics of motor performances. However, the interplay between these kinematic variations and the social cues provided by eye gaze has not been properly assessed yet. In the present study, we tested whether limiting the access to eye gaze altered the motor-related effects of social intention on motor performances. In a dyadic interaction, the agents' task was to displace a dummy glass to a new position with the intention to fill it themselves (personal intention) or having it filled by the observers facing them (social intention). The observers performed their action only when they were able to identify a social intention in agents' action. The task was performed while having access to observers' eye gaze or not, through the manipulation of an occluder. Results showed an effect of social intention on agents' motor performances, that induced an amplification of the kinematic spatio-temporal parameters. Such amplification was smaller when the observers' eye gaze was not available. In this latter condition, the identification of the social intention in the observed actions was impaired. Altogether, the results suggest that the presence of eye gaze cues contributes significantly to the success of social interaction, by facilitating the expression and the understanding of social intentions through the kinematics of object-directed actions.

Attention Drives Visual Processing and Audiovisual Integration During Multimodal Communication

During communication in real-life settings, our brain often needs to integrate auditory and visual information and at the same time actively focus on the relevant sources of information, while ignoring interference from irrelevant events. The interaction between integration and attention processes remains poorly understood. Here, we use rapid invisible frequency tagging and magnetoencephalography to investigate how attention affects auditory and visual information processing and integration, during multimodal communication. We presented human participants (male and female) with videos of an actress uttering action verbs (auditory; tagged at 58 Hz) accompanied by two movie clips of hand gestures on both sides of fixation (attended stimulus tagged at 65 Hz; unattended stimulus tagged at 63 Hz). Integration difficulty was manipulated by a lower-order auditory factor (clear/degraded speech) and a higher-order visual semantic factor (matching/mismatching gesture). We observed an enhanced neural response to the attended visual information during degraded speech compared to clear speech. For the unattended information, the neural response to mismatching gestures was enhanced compared to matching gestures. Furthermore, signal power at the intermodulation frequencies of the frequency tags, indexing nonlinear signal interactions, was enhanced in the left frontotemporal and frontal regions. Focusing on the left inferior frontal gyrus, this enhancement was specific for the attended information, for those trials that benefitted from integration with a matching gesture. Together, our results suggest that attention modulates audiovisual processing and interaction, depending on the congruence and quality of the sensory input.

Gestures speed up responses to questions

Most language use occurs in face-to-face conversation, which involves rapid turn-taking. Seeing communicative bodily signals in addition to hearing speech may facilitate such fast responding. We tested whether this holds for co-speech hand gestures by investigating whether these gestures speed up button press responses to questions. Sixty native speakers of Dutch viewed videos in which an actress asked yes/no-questions, either with or without a corresponding iconic hand gesture. Participants answered the questions as quickly and accurately as possible via button press. Gestures did not impact response accuracy, but crucially, gestures sped up responses, suggesting that response planning may be finished earlier when gestures are seen. How much gestures sped up responses was not related to their timing in the question or their timing with respect to the corresponding information in speech. Overall, these results are in line with the idea that multimodality may facilitate fast responding during face-to-face conversation.

The impact of internal-generated contextual clues on EFL vocabulary learning: insights from EEG

With the popularity of learning vocabulary online among English as a Foreign Language (EFL) learners today, educators and researchers have been considering ways to enhance the effectiveness of this approach. Prior research has underscored the significance of contextual clues in vocabulary acquisition. However, few studies have compared the context provided by instructional materials and that generated by learners themselves. Hence, this present study sought to explore the impact of internal-generated contextual clues in comparison to those provided by instructional materials on EFL learners' online vocabulary acquisition. A total of 26 university students were enrolled and underwent electroencephalography (EEG). Based on a within-subjects design, all participants learned two groups of vocabulary words through a series of video clips under two conditions: one where the contexts were externally provided and the other where participants themselves generated the contexts. In this regard, participants were tasked with either viewing contextual clues presented on the screen or creating their own contextual clues for word comprehension. EEG signals were recorded during the learning process to explore neural activities, and post-tests were conducted to assess learning performance after each vocabulary learning session. Our behavioral results indicated that comprehending words with internal-generated contextual clues resulted in superior learning performance compared to using context provided by instructional materials. Furthermore, EEG data revealed that learners expended greater cognitive resources and mental effort in semantically integrating the meaning of words when they self-created contextual clues, as evidenced by stronger alpha and beta-band oscillations. Moreover, the stronger alpha-band oscillations and lower inter-subject correlation (ISC) among learners suggested that the generative task of creating context enhanced their top-down attentional control mechanisms and selective visual processing when learning vocabulary from videos. These findings underscored the positive effects of internal-generated contextual clues, indicating that instructors should encourage learners to construct their own contexts in online EFL vocabulary instruction rather than providing pre-defined contexts. Future research should aim to explore the limits and conditions of employing these two types of contextual clues in online EFL vocabulary learning. This could be achieved by manipulating the quality and understandability of contexts and considering learners' language proficiency levels.

Neural Representations of Non-native Speech Reflect Proficiency and Interference from Native Language Knowledge

Learning to process speech in a foreign language involves learning new representations for mapping the auditory signal to linguistic structure. Behavioral experiments suggest that even listeners that are highly proficient in a non-native language experience interference from representations of their native language. However, much of the evidence for such interference comes from tasks that may inadvertently increase the salience of native language competitors. Here we tested for neural evidence of proficiency and native language interference in a naturalistic story listening task. We studied electroencephalography responses of 39 native speakers of Dutch (14 male) to an English short story, spoken by a native speaker of either American English or Dutch. We modeled brain responses with multivariate temporal response functions, using acoustic and language models. We found evidence for activation of Dutch language statistics when listening to English, but only when it was spoken with a Dutch accent. This suggests that a naturalistic, monolingual setting decreases the interference from native language representations, whereas an accent in the listener's own native language may increase native language interference, by increasing the salience of the native language and activating native language phonetic and lexical representations. Brain responses suggest that such interference stems from words from the native language competing with the foreign language in a single word recognition system, rather than being activated in a parallel lexicon. We further found that secondary acoustic representations of speech (after 200 ms latency) decreased with increasing proficiency. This may reflect improved acoustic-phonetic models in more proficient listeners.Significance Statement Behavioral experiments suggest that native language knowledge interferes with foreign language listening, but such effects may be sensitive to task manipulations, as tasks that increase metalinguistic awareness may also increase native language interference. This highlights the need for studying non-native speech processing using naturalistic tasks. We measured neural responses unobtrusively while participants listened for comprehension and characterized the influence of proficiency at multiple levels of representation. We found that salience of the native language, as manipulated through speaker accent, affected activation of native language representations: significant evidence for activation of native language (Dutch) categories was only obtained when the speaker had a Dutch accent, whereas no significant interference was found to a speaker with a native (American) accent.

Hand Gestures Have Predictive Potential During Conversation: An Investigation of the Timing of Gestures in Relation to Speech

During face-to-face conversation, transitions between speaker turns are incredibly fast. These fast turn exchanges seem to involve next speakers predicting upcoming semantic information, such that next turn planning can begin before a current turn is complete. Given that face-to-face conversation also involves the use of communicative bodily signals, an important question is how bodily signals such as co-speech hand gestures play into these processes of prediction and fast responding. In this corpus study, we found that hand gestures that depict or refer to semantic information started before the corresponding information in speech, which held both for the onset of the gesture as a whole, as well as the onset of the stroke (the most meaningful part of the gesture). This early timing potentially allows listeners to use the gestural information to predict the corresponding semantic information to be conveyed in speech. Moreover, we provided further evidence that questions with gestures got faster responses than questions without gestures. However, we found no evidence for the idea that how much a gesture precedes its lexical affiliate (i.e., its predictive potential) relates to how fast responses were given. The findings presented here highlight the importance of the temporal relation between speech and gesture and help to illuminate the potential mechanisms underpinning multimodal language processing during face-to-face conversation.

The role of multimodal cues in second language comprehension

In face-to-face communication, multimodal cues such as prosody, gestures, and mouth movements can play a crucial role in language processing. While several studies have addressed how these cues contribute to native (L1) language processing, their impact on non-native (L2) comprehension is largely unknown. Comprehension of naturalistic language by L2 comprehenders may be supported by the presence of (at least some) multimodal cues, as these provide correlated and convergent information that may aid linguistic processing. However, it is also the case that multimodal cues may be less used by L2 comprehenders because linguistic processing is more demanding than for L1 comprehenders, leaving more limited resources for the processing of multimodal cues. In this study, we investigated how L2 comprehenders use multimodal cues in naturalistic stimuli (while participants watched videos of a speaker), as measured by electrophysiological responses (N400) to words, and whether there are differences between L1 and L2 comprehenders. We found that prosody, gestures, and informative mouth movements each reduced the N400 in L2, indexing easier comprehension. Nevertheless, L2 participants showed weaker effects for each cue compared to L1 comprehenders, with the exception of meaningful gestures and informative mouth movements. These results show that L2 comprehenders focus on specific multimodal cues - meaningful gestures that support meaningful interpretation and mouth movements that enhance the acoustic signal - while using multimodal cues to a lesser extent than L1 comprehenders overall.

The role of manual gestures in second language comprehension: a simultaneous interpreting experiment

Manual gestures and speech form a single integrated system during native language comprehension. However, it remains unclear whether this hold for second language (L2) comprehension, more specifically for simultaneous interpreting (SI), which involves comprehension in one language and simultaneous production in another. In a combined mismatch and priming paradigm, we presented Swedish speakers fluent in L2 English with multimodal stimuli in which speech was congruent or incongruent with a gesture. A picture prime was displayed before the stimuli. Participants had to decide whether the video was related to the prime, focusing either on the auditory or the visual information. Participants performed the task either during passive viewing or during SI into their L1 Swedish (order counterbalanced). Incongruent stimuli yielded longer reaction times than congruent stimuli, during both viewing and interpreting. Visual and audio targets were processed equally easily in both activities. However, in both activities incongruent speech was more disruptive for gesture processing than incongruent gesture was for speech processing. Thus, the data only partly supports the expected mutual and obligatory interaction of gesture and speech in L2 comprehension. Interestingly, there were no differences between activities suggesting that the language comprehension component in SI shares features with other (L2) comprehension tasks.

Visual-Auditory Integration and High-Variability Speech Can Facilitate Mandarin Chinese Tone Identification

PURPOSE

Previous studies have demonstrated that tone identification can be facilitated when auditory tones are integrated with visual information that depicts the pitch contours of the auditory tones (hereafter, visual effect). This study investigates this visual effect in combined visual-auditory integration with high- and low-variability speech and examines whether one's prior tonal-language learning experience shapes the strength of this visual effect.

METHOD

Thirty Mandarin-naïve listeners, 25 Mandarin second language learners, and 30 native Mandarin listeners participated in a tone identification task in which participants judged whether an auditory tone was rising or falling in pitch. Moving arrows depicted the pitch contours of the auditory tones. A priming paradigm was used with the target auditory tones primed by four multimodal conditions: no stimuli (A-V-), visual-only stimuli (A-V+), auditory-only stimuli (A+V-), and both auditory and visual stimuli (A+V+).

RESULTS

For Mandarin naïve listeners, the visual effect in accuracy produced under the cross-modal integration (A+V+ vs. A+V-) was superior to a unimodal approach (A-V+ vs. A-V-), as evidenced by a higher d prime of A+V+ as opposed to A+V-. However, this was not the case in response time. Additionally, the visual effect in accuracy and response time under the unimodal approach only occurred for high-variability speech, not for low-variability speech. Across the three groups of listeners, we found that the less tonal-language learning experience one had, the stronger the visual effect.

CONCLUSION

Our study revealed the visual-auditory advantage and disadvantage of the visual effect and the joint contribution of visual-auditory integration and high-variability speech on facilitating tone perception via the process of speech symbolization and categorization.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21357729.

Mask wearing in Japanese and French nursery schools: The perceived impact of masks on communication

Due to the global COVID-19 pandemic, covering the mouth region with a face mask became pervasive in many regions of the world, potentially impacting how people communicate with and around children. To explore the characteristics of this masked communication, we asked nursery school educators, who have been at the forefront of daily masked interaction with children, about their perception of daily communicative interactions while wearing a mask in an online survey. We collected data from French and Japanese nursery school educators to gain an understanding of commonalities and differences in communicative behavior with face masks given documented cultural differences in pre-pandemic mask wearing habits, face scanning patterns, and communicative behavior. Participants (177 French and 138 Japanese educators) reported a perceived change in their own communicative behavior while wearing a mask, with decreases in language quantity and increases in language quality and non-verbal cues. Comparable changes in their team members’ and children’s communicative behaviors were also reported. Moreover, our results suggest that these changes in educators’ communicative behaviors are linked to their attitudes toward mask wearing and their potential difficulty in communicating following its use. These findings shed light on the impact of pandemic-induced mask wearing on children’s daily communicative environment.

The role of iconic gestures and mouth movements in face-to-face communication

Human face-to-face communication is multimodal: it comprises speech as well as visual cues, such as articulatory and limb gestures. In the current study, we assess how iconic gestures and mouth movements influence audiovisual word recognition. We presented video clips of an actress uttering single words accompanied, or not, by more or less informative iconic gestures. For each word we also measured the informativeness of the mouth movements from a separate lipreading task. We manipulated whether gestures were congruent or incongruent with the speech, and whether the words were audible or noise vocoded. The task was to decide whether the speech from the video matched a previously seen picture. We found that congruent iconic gestures aided word recognition, especially in the noise-vocoded condition, and the effect was larger (in terms of reaction times) for more informative gestures. Moreover, more informative mouth movements facilitated performance in challenging listening conditions when the speech was accompanied by gestures (either congruent or incongruent) suggesting an enhancement when both cues are present relative to just one. We also observed (a trend) that more informative mouth movements speeded up word recognition across clarity conditions, but only when the gestures were absent. We conclude that listeners use and dynamically weight the informativeness of gestures and mouth movements available during face-to-face communication.

Effects of training and using an audio-tactile sensory substitution device on speech-in-noise understanding

Understanding speech in background noise is challenging. Wearing face-masks, imposed by the COVID19-pandemics, makes it even harder. We developed a multi-sensory setup, including a sensory substitution device (SSD) that can deliver speech simultaneously through audition and as vibrations on the fingertips. The vibrations correspond to low frequencies extracted from the speech input. We trained two groups of non-native English speakers in understanding distorted speech in noise. After a short session (30-45 min) of repeating sentences, with or without concurrent matching vibrations, we showed comparable mean group improvement of 14-16 dB in Speech Reception Threshold (SRT) in two test conditions, i.e., when the participants were asked to repeat sentences only from hearing and also when matching vibrations on fingertips were present. This is a very strong effect, if one considers that a 10 dB difference corresponds to doubling of the perceived loudness. The number of sentence repetitions needed for both types of training to complete the task was comparable. Meanwhile, the mean group SNR for the audio-tactile training (14.7 ± 8.7) was significantly lower (harder) than for the auditory training (23.9 ± 11.8), which indicates a potential facilitating effect of the added vibrations. In addition, both before and after training most of the participants (70-80%) showed better performance (by mean 4-6 dB) in speech-in-noise understanding when the audio sentences were accompanied with matching vibrations. This is the same magnitude of multisensory benefit that we reported, with no training at all, in our previous study using the same experimental procedures. After training, performance in this test condition was also best in both groups (SRT ~ 2 dB). The least significant effect of both training types was found in the third test condition, i.e. when participants were repeating sentences accompanied with non-matching tactile vibrations and the performance in this condition was also poorest after training. The results indicate that both types of training may remove some level of difficulty in sound perception, which might enable a more proper use of speech inputs delivered via vibrotactile stimulation. We discuss the implications of these novel findings with respect to basic science. In particular, we show that even in adulthood, i.e. long after the classical "critical periods" of development have passed, a new pairing between a certain computation (here, speech processing) and an atypical sensory modality (here, touch) can be established and trained, and that this process can be rapid and intuitive. We further present possible applications of our training program and the SSD for auditory rehabilitation in patients with hearing (and sight) deficits, as well as healthy individuals in suboptimal acoustic situations.

Covert Attention to Gestures Is Sufficient for Information Uptake

Numerous studies have explored the benefit of iconic gestures in speech comprehension. However, only few studies have investigated how visual attention was allocated to these gestures in the context of clear versus degraded speech and the way information is extracted for enhancing comprehension. This study aimed to explore the effect of iconic gestures on comprehension and whether fixating the gesture is required for information extraction. Four types of gestures (i.e., semantically and syntactically incongruent iconic gestures, meaningless configurations, and congruent iconic gestures) were presented in a sentence context in three different listening conditions (i.e., clear, partly degraded or fully degraded speech). Using eye tracking technology, participants’ gaze was recorded, while they watched video clips after which they were invited to answer simple comprehension questions. Results first showed that different types of gestures differently attract attention and that the more speech was degraded, the less participants would pay attention to gestures. Furthermore, semantically incongruent gestures appeared to particularly impair comprehension although not being fixated while congruent gestures appeared to improve comprehension despite also not being fixated. These results suggest that covert attention is sufficient to convey information that will be processed by the listener.

The Role of Iconic Gestures in Speech Comprehension: An Overview of Various Methodologies

Iconic gesture-speech integration is a relatively recent field of investigation with numerous researchers studying its various aspects. The results obtained are just as diverse. The definition of iconic gestures is often overlooked in the interpretations of results. Furthermore, while most behavioral studies have demonstrated an advantage of bimodal presentation, brain activity studies show a diversity of results regarding the brain regions involved in the processing of this integration. Clinical studies also yield mixed results, some suggesting parallel processing channels, others a unique and integrated channel. This review aims to draw attention to the methodological variations in research on iconic gesture-speech integration and how they impact conclusions regarding the underlying phenomena. It will also attempt to draw together the findings from other relevant research and suggest potential areas for further investigation in order to better understand processes at play during speech integration process.

Rapid invisible frequency tagging reveals nonlinear integration of auditory and visual information

During communication in real-life settings, the brain integrates information from auditory and visual modalities to form a unified percept of our environment. In the current magnetoencephalography (MEG) study, we used rapid invisible frequency tagging (RIFT) to generate steady-state evoked fields and investigated the integration of audiovisual information in a semantic context. We presented participants with videos of an actress uttering action verbs (auditory; tagged at 61 Hz) accompanied by a gesture (visual; tagged at 68 Hz, using a projector with a 1,440 Hz refresh rate). Integration difficulty was manipulated by lower-order auditory factors (clear/degraded speech) and higher-order visual factors (congruent/incongruent gesture). We identified MEG spectral peaks at the individual (61/68 Hz) tagging frequencies. We furthermore observed a peak at the intermodulation frequency of the auditory and visually tagged signals (fvisual - fauditory  = 7 Hz), specifically when lower-order integration was easiest because signal quality was optimal. This intermodulation peak is a signature of nonlinear audiovisual integration, and was strongest in left inferior frontal gyrus and left temporal regions; areas known to be involved in speech-gesture integration. The enhanced power at the intermodulation frequency thus reflects the ease of lower-order audiovisual integration and demonstrates that speech-gesture information interacts in higher-order language areas. Furthermore, we provide a proof-of-principle of the use of RIFT to study the integration of audiovisual stimuli, in relation to, for instance, semantic context.

Gesture Use and Processing: A Review on Individual Differences in Cognitive Resources

Speakers use spontaneous hand gestures as they speak and think. These gestures serve many functions for speakers who produce them as well as for listeners who observe them. To date, studies in the gesture literature mostly focused on group-comparisons or the external sources of variation to examine when people use, process, and benefit from using and observing gestures. However, there are also internal sources of variation in gesture use and processing. People differ in how frequently they use gestures, how salient their gestures are, for what purposes they produce gestures, and how much they benefit from using and seeing gestures during comprehension and learning depending on their cognitive dispositions. This review addresses how individual differences in different cognitive skills relate to how people employ gestures in production and comprehension across different ages (from infancy through adulthood to healthy aging) from a functionalist perspective. We conclude that speakers and listeners can use gestures as a compensation tool during communication and thinking that interacts with individuals' cognitive dispositions.

Beat Gestures for Comprehension and Recall: Differential Effects of Language Learners and Native Listeners

Previous work has shown how native listeners benefit from observing iconic gestures during speech comprehension tasks of both degraded and non-degraded speech. By contrast, effects of the use of gestures in non-native listener populations are less clear and studies have mostly involved iconic gestures. The current study aims to complement these findings by testing the potential beneficial effects of beat gestures (non-referential gestures which are often used for information- and discourse marking) on language recall and discourse comprehension using a narrative-drawing task carried out by native and non-native listeners. Using a within-subject design, 51 French intermediate learners of English participated in a narrative-drawing task. Each participant was assigned 8 videos to watch, where a native speaker describes the events of a short comic strip. Videos were presented in random order, in four conditions: in Native listening conditions with frequent, naturally-modeled beat gestures, in Native listening conditions without any gesture, in Non-native listening conditions with frequent, naturally-modeled beat gestures, and in Non-native listening conditions without any gesture. Participants watched each video twice and then immediately recreated the comic strip through their own drawings. Participants' drawings were then evaluated for discourse comprehension (via their ability to convey the main goals of the narrative through their drawings) and recall (via the number of gesturally-marked elements in the narration that were included in their drawings). Results showed that for native listeners, beat gestures had no significant effect on either recall or comprehension. In non-native speech, however, beat gestures led to significantly lower comprehension and recall scores. These results suggest that frequent, naturally-modeled beat gestures in longer discourses may increase cognitive load for language learners, resulting in negative effects on both memory and language understanding. These findings add to the growing body of literature that suggests that gesture benefits are not a "one-size-fits-all" solution, but rather may be contingent on factors such as language proficiency and gesture rate, particularly in that whenever beat gestures are repeatedly used in discourse, they inherently lose their saliency as markers of important information.

Gesture, communication, and adult acquired hearing loss

Nonverbal communication, specifically hand and arm movements (commonly known as gesture), has long been recognized and explored as a significant element in human interaction as well as potential compensatory behavior for individuals with communication difficulties. The use of gesture as a compensatory communication method in expressive and receptive human communication disorders has been the subject of much investigation. Yet within the context of adult acquired hearing loss, gesture has received limited research attention and much remains unknown about patterns of nonverbal behaviors in conversations in which hearing loss is a factor. This paper presents key elements of the background of gesture studies and the theories of gesture function and production followed by a review of research focused on adults with hearing loss and the role of gesture and gaze in rehabilitation. The current examination of the visual resource of co-speech gesture in the context of everyday interactions involving adults with acquired hearing loss suggests the need for the development of an evidence base to effect enhancements and changes in the way in which rehabilitation services are conducted.

An Eye-Tracking Study on Audiovisual Speech Perception Strategies Adopted by Normal-Hearing and Deaf Adults Under Different Language Familiarities

Purpose The primary purpose of this study was to explore the audiovisual speech perception strategies.80.23.47 adopted by normal-hearing and deaf people in processing familiar and unfamiliar languages. Our primary hypothesis was that they would adopt different perception strategies due to different sensory experiences at an early age, limitations of the physical device, and the developmental gap of language, and others. Method Thirty normal-hearing adults and 33 prelingually deaf adults participated in the study. They were asked to perform judgment and listening tasks while watching videos of a Uygur-Mandarin bilingual speaker in a familiar language (Standard Chinese) or an unfamiliar language (Modern Uygur) while their eye movements were recorded by eye-tracking technology. Results Task had a slight influence on the distribution of selective attention, whereas subject and language had significant influences. To be specific, the normal-hearing and the d10eaf participants mainly gazed at the speaker's eyes and mouth, respectively, in the experiment; moreover, while the normal-hearing participants had to stare longer at the speaker's mouth when they confronted with the unfamiliar language Modern Uygur, the deaf participant did not change their attention allocation pattern when perceiving the two languages. Conclusions Normal-hearing and deaf adults adopt different audiovisual speech perception strategies: Normal-hearing adults mainly look at the eyes, and deaf adults mainly look at the mouth. Additionally, language and task can also modulate the speech perception strategy.