Enhanced amplitude modulations contribute to the Lombard intelligibility benefit: Evidence from the Nijmegen Corpus of Lombard Speech

Speakers adjust their voice when talking in noise, which is known as Lombard speech. These acoustic adjustments facilitate speech comprehension in noise relative to plain speech (i.e., speech produced in quiet). However, exactly which characteristics of Lombard speech drive this intelligibility benefit in noise remains unclear. This study assessed the contribution of enhanced amplitude modulations to the Lombard speech intelligibility benefit by demonstrating that (1) native speakers of Dutch in the Nijmegen Corpus of Lombard Speech (NiCLS) produce more pronounced amplitude modulations in noise vs. in quiet; (2) more enhanced amplitude modulations correlate positively with intelligibility in a speech-in-noise perception experiment; (3) transplanting the amplitude modulations from Lombard speech onto plain speech leads to an intelligibility improvement, suggesting that enhanced amplitude modulations in Lombard speech contribute towards intelligibility in noise. Results are discussed in light of recent neurobiological models of speech perception with reference to neural oscillators phase-locking to the amplitude modulations in speech, guiding the processing of speech

Listeners normalize speech for contextual speech rate even without an explicit recognition task

Speech can be produced at different rates. Listeners take this rate variation into account by normalizing vowel duration for contextual speech rate: An ambiguous Dutch word /m?t/ is perceived as short /mAt/ when embedded in a slow context, but long /ma:t/ in a fast context. Whilst some have argued that this rate normalization involves low-level automatic perceptual processing, there is also evidence that it arises at higher-level cognitive processing stages, such as decision making. Prior research on rate-dependent speech perception has only used explicit recognition tasks to investigate the phenomenon, involving both perceptual processing and decision making. This study tested whether speech rate normalization can be observed without explicit decision making, using a cross-modal repetition priming paradigm. Results show that a fast precursor sentence makes an embedded ambiguous prime (/m?t/) sound (implicitly) more /a:/-like, facilitating lexical access to the long target word "maat" in a (explicit) lexical decision task. This result suggests that rate normalization is automatic, taking place even in the absence of an explicit recognition task. Thus, rate normalization is placed within the realm of everyday spoken conversation, where explicit categorization of ambiguous sounds is rare

Fluency in dialogue: Turn‐taking behavior shapes perceived fluency in native and nonnative speech

Fluency is an important part of research on second language learning, but most research on language proficiency typically has not included oral fluency as part of interaction, even though natural communication usually occurs in conversations. The present study considered aspects of turn-taking behavior as part of the construct of fluency and investigated whether these aspects differentially influence perceived fluency ratings of native and non-native speech. Results from two experiments using acoustically manipulated speech showed that, in native speech, too ‘eager’ (interrupting a question with a fast answer) and too ‘reluctant’ answers (answering slowly after a long turn gap) negatively affected fluency ratings. However, in non-native speech, only too ‘reluctant’ answers led to lower fluency ratings. Thus, we demonstrate that acoustic properties of dialogue are perceived as part of fluency. By adding to our current understanding of dialogue fluency, these lab-based findings carry implications for language teaching and assessmen

Breast implant causes allergic contact dermatitis or foreign body reaction?

In this case report we describe a 55-year-old Caucasian female who had developed an itching, erythematous plaque on the right breast seven months after she received a permanent tissue expander. Topical corticosteroids had no effect upon which a capsulectomy was performed and the complaints disappeared

Selective attention to a specific talker does not change the effect of surrounding acoustic context

Spoken sentences contain considerable prosodic variation, for instance in their speech rate [1]. One mechanism by which the listener can overcome such variation is by interpreting the durations of speech sounds relative to the surrounding speech rate. Indeed, in a fast context, a durationally ambiguous sound is perceived as longer than in a slow context [2]. In abstractionist models of spoken word comprehension, this process – known as rate normalization – affects pre-lexical representations before abstract phonological representations are accessed [3]. A recent study [4] provided support for such an early perceptual locus of rate normalization. In that study, participants performed a visual search task that induced high (large grid) vs. low (small grid) cognitive load, while listening to fast and slow context sentences. Context sentences were followed by durationally ambiguous targets. Fast sentences were shown to bias target perception towards more ‘long’ target segments than slow contexts. Critically, changes in cognitive load did not modulate this rate effect. These findings support a model in which normalization processes arise early during perceptual processing; too early to be affected by attentional modulation. The present study further evaluated the cognitive locus of normalization processes by testing the influence of another form of attention: auditory stream segregation. Specifically, if listeners are presented with a fast and a slow talker at the same time but in different ears, does explicitly attending to one or the other stream influence target perception? The aforementioned model [4] predicts that selective attention should not influence target perception, since normalization processes should be robust against changes in attention allocation. Alternatively, if attention does modulate normalization processes, two participants, one attending to fast, the other to slow speech, should show different perception. Dutch participants (Expt 1: N=32; Expt 2: N=16; Expt 3: N=16) were presented with 200 fast and slow context sentences of various lengths, followed by a target duration continuum ambiguous between, e.g., short target “geven” /ˈxevə/ give vs. long target “gegeven” /xəˈxevə/ given (i.e., 20 target pairs differing presence/absence of unstressed syllable /xə-/). Critically, in Experiment 1, participants heard two talkers simultaneously (talker and location counter-balanced across participants), one (relatively long) sentence at a fast rate, and one (half as long) sentence at a slow rate (rate varied within participants). Context sentences were followed by ambiguous targets from yet another talker (Fig. 1). Half of the participants was instructed to attend to talker A, while the other half attended to talker B. Thus, participants heard identical auditory stimuli, but varied in which talker they attended to. Debriefing questionnaires and transcriptions of attended talkers in filler trials confirmed that participants successfully attended to one talker, and ignored the other. Nevertheless, no effect of attended rate was found (Fig. 2; p>.9), indicating that modulation of attention did not influence participants’ rate normalization. Control experiments showed that it was possible to obtain rate effects with single talker contexts that were either talker-incongruent (Expt 2) or talker-congruent (Expt 3) with the following target (Fig. 1). In both of these experiments, there was a higher proportion of long target responses following a fast context (Fig. 2). This shows that contextual rate affected the perception of syllabic duration and that talker-congruency with the target did not change the effect. Therefore, in line with [4], the current experiments suggest that normalization processes arise early in perception, and are robust against changes in attention

Modelling human factors in perceptual multimedia quality: On the role of personality and culture

Perception of multimedia quality is shaped by a rich interplay between system, context, and human factors. While system and context factors are widely researched, few studies in this area consider human factors as sources of systematic variance. This paper presents an analysis on the influence of personality (Five-Factor Model) and cultural traits (Hofstede Model) on the perception of multimedia quality. A set of 144 video sequences (from 12 short movie excerpts) were rated by 114 participants from a cross-cultural population, producing 1232 ratings. On this data, three models are compared: a baseline model that only considers system factors; an extended model that includes personality and culture as human factors; and an optimistic model in which each participant is modeled as a random effect. An analysis shows that personality and cultural traits represent 9.3% of the variance attributable to human factors while human factors overall predict an equal or higher proportion of variance compared to system factors. In addition, the quality-enjoyment correlation varied across the movie excerpts. This suggests that human factors play an important role in perceptual multimedia quality, but further research to explore moderation effects and a broader range of human factors is warranted