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Global stress is widespread in today’s post-pandemic world of political and economic uncertainty. Vibroacoustic technology is a vibrotactile intervention with multiple uses, but its impact on stress lacks interpretation. This research assessed if the vibroacoustic technology of a Vibroacoustic Sound Massage (VSM) can reduce psychological, physiological, and cognitive stress. The Perceived Stress Scale (PSS-10) and electrocardiogram (ECG) and electroencephalogram (EEG) biosignals were used to quantify results. Participants were divided into Low-Stress and High-Stress groups. The ECG results show VSM increased parasympathetic activity for all participants, with the Low-Stress group being more affected. The EEG results indicate increased concentration, reduced arousal, and increased relaxation, with participant well-being non-significantly affected, though variability in this metric was homogenised after VSM. Together, these results validate VSM as an effective support tool for stress management; however, further research is required.

Practicing public speaking to simulated audiences created in virtual reality environments is reported to be effective for reducing public speaking anxiety. However, little is known about whether this effect can be enhanced by encouraging the use of gestures during VR-assisted public speaking training. In the present study two groups of secondary schools underwent a three-session public speaking training program in which they delivered short speeches to VR-simulated audiences. One group was encouraged to “embody” their speeches through gesture while the other was given no instructions regarding the use of gesture. Before and after the training sessions participants underwent respectively a pre- and a post-training session, which consisted of delivering a similar short speech to a small live audience. At pre- and post-training sessions, participants’ levels of anxiety were self-assessed, their speech performances were rated for persuasiveness and charisma by independent raters, and their verbal output was analyzed for prosodic features and gesture rate. Results showed that both groups significantly reduced their self-assessed anxiety between the pre- and post-training sessions. Persuasiveness and charisma ratings increased for both groups, but to a significantly greater extent in the gesture-using group. However, the prosodic and gestural features analyzed showed no significant differences across groups or from pre-to post-training speeches. Thus, our results seem to indicate that encouraging the use of gesture in VR-assisted public speaking practice can help students be more charismatic and their delivery more persuasive before presenting in front of a live audience.

This study examines whether a social robot can enable team creativity and increase team performance depending on its speaking style. The aim is to provide insight into human teams' creativity and performance when exposed to different ways of speaking by a social robot, that is, when the robotic creativity facilitator is using different acoustic-prosodic features. In one condition, participants received their instructions from the robot in a “charismatic” speaking style, in the other, the robot used a less engaging way of speaking. The results show that when the robot's speech is based on charismatic speech characteristics, it is significantly better at enhancing team creativity and performance than when its speech uses fewer charismatic speech characteristics. The robot's speaking style thus influences its effectiveness as team creativity facilitator.

IntroductionCalls via video apps, mobile phones and similar digital channels are a rapidly growing form of speech communication. Such calls are not only— and perhaps less and less— about exchanging content, but about creating, maintaining, and expanding social and business networks. In the phonetic code of speech, these social and emotional signals are considerably shaped by (or encoded in) prosody. However, according to previous studies, it is precisely this prosody that is significantly distorted by modern compression codecs. As a result, the identification of emotions becomes blurred and can even be lost to the extent that opposing emotions like joy and anger or disgust and sadness are no longer differentiated on the recipients' side. The present study searches for the acoustic origins of these perceptual findings.MethodA set of 108 sentences from the Berlin Database of Emotional Speech served as speech material in our study. The sentences were realized by professional actors (2m, 2f) with seven different emotions (neutral, fear, disgust, joy, boredom, anger, sadness) and acoustically analyzed in the original uncompressed (WAV) version and as well as in strongly compressed versions based on the four popular codecs AMR-WB, MP3, OPUS, and SPEEX. The analysis included 6 tonal (i.e. f0-related) and 7 non-tonal prosodic parameters (e.g., formants as well as acoustic-energy and spectral-slope estimates).ResultsResults show significant, codec-specific distortion effects on all 13 prosodic parameter measurements compared to the WAV reference condition. Means values of automatic measurement can, across sentences, deviate by up to 20% from the values of the WAV reference condition. Moreover, the effects go in opposite directions for tonal and non-tonal parameters. While tonal parameters are distorted by speech compression such that the acoustic differences between emotions are increased, compressing non-tonal parameters make the acoustic-prosodic profiles of emotions more similar to each other, particularly under MP3 and SPEEX compression.DiscussionThe term “flat affect” comes from the medical field and describes a person's inability to express or display emotions. So, does strong compression of emotional speech create a “digital flat affect”? The answer to this question is a conditional “yes”. We provided clear evidence for a “digital flat affect”. However, it seems less strongly pronounced in the present acoustic measurements than in previous perception data, and it manifests itself more strongly in non-tonal than in tonal parameters. We discuss the practical implications of our findings for the everyday use of digital communication devices and critically reflect on the generalizability of our findings, also with respect to their origins in the codecs' inner mechanics.

Public speaking is fundamental in our daily life, and it happens to be challenging for many people. Like all aspects of language, these skills should be encouraged early on in educational settings. However, the high number of students per class and the extensive curriculum both limit the possibilities of the training and, moreover, entail that students give short in-class presentations under great time pressure. Virtual Reality (VR) environments can help speakers and teachers meet these challenges and foster oral skills. This experimental study employs a between-subjects pre- and post-training design with four Catalan high-school student groups, a VR group (N = 30) and a Non-VR group (N = 20). Both groups gave a 2-min speech in front of a live audience before (pre-training) and after (post-training) 3 training sessions (one session per week) in which they practiced public speaking either in front of a VR audience or alone in a classroom (Non-VR). Students assessed their anxiety measures right before performing every speech and filled out a satisfaction questionnaire at the end. Pre- and post-training speeches were assessed by 15 raters, who analyzed the persuasiveness of the message and the charisma of the presenter. Speeches were also analyzed for prosodic features and gesture rate. First, results showed that self-assessed anxiety got significantly reduced at post-training for both conditions. Second, acoustic analyses of both groups' speeches show that the VR group has, unlike the Non-VR group, developed a more clear and resonant voice quality in the post-training speeches, in terms of higher cepstral-peak prominence (CPP) (although no significant differences in f0- related parameters as a function of training were obtained), as well as significantly less erosion effects than the Non-VR group. However, these differences across groups did not trigger a direct improvement on the participants' gesture rate, persuasiveness and charisma at post-training. Furthermore, students perceived the training in the VR environment to be more useful and beneficial for their future oral presentations than the Non-VR group. All in all, short unguided VR training sessions can help students feel less anxious, promote a more clear and resonant voice style, and can prevent them from experiencing an erosion effect while practicing speeches in front of a real audience.

In the present work, we describe and discuss two studies in the field of motivating-speech research. The studies investigate voice-quality features (study 1) and pragmatic aspects (study 2) in German motivating speech, thereby adding to the current state-of-the-art in understanding motivating speech and language1. We find indications that a low amount of breathiness, a more periodic signal and a balanced distribution of specific pragmatic elements contribute to a motivating impact in German.

Much previous research suggests that teachers’ individual characteristics may affect students’ performance; however, which factors are particularly helpful is as yet unclear and methodologically very difficult to assess. In this paper, we study the effects of robots’ speaking styles when instructing students on a task. 40 participants saw a brief video in which a robot presented its instructions either in a charismatic or a not so charismatic speaking style. Participants’ task was then to produce foreign language sentences on the basis of visualizations of the prosodic properties of these sentences. A subsequent analysis of participants’ productions shows that language learners’ performance was significantly better when the robot had delivered its instructions in a charismatic voice. The results suggest not only that a charismatic speaking style may be crucial for teachers in general and hence one of the factors causing the interpersonal variation between teachers, but also that students can benefit from instructions by robots delivered in a charismatic speaking style.

Charisma is a complex phenomenon. This fact manifests itself not least in an abundance of myths, half-truths, and unanswered research questions. Most charisma myths have not been uncontroversial, and since empirical investigations have advanced quickly over the past years, we take the opportunity in this paper to revisit ten of the most important myths that relate primarily, but not exclusively, to the linguistic and phonetic aspects of charisma, such as the interactions between verbal and nonverbal and between segmental and prosodic cues, as well as the roles of breathing and fundamental frequency in charisma perception. The result is a very diverse picture. Some myths, including very old ones, can be accepted. Others must be rejected in the light of contradicting empirical results. The status of some myths remains unsettled. Furthermore, in discussing that diverse picture, our paper points towards knowledge gaps in research and practice and gives concrete directions as to where to go from here.

Remote meetings via Zoom, Skype, or Teams limit the range and richness of nonverbal communication signals. Not just because of the typically sub-optimal light, posture, and gaze conditions, but also because of the reduced speaker visibility. Consequently, the speaker’s voice becomes immensely important, especially when it comes to being persuasive and conveying charismatic attributes. However, to offer a reliable service and limit the transmission bandwidth, remote meeting tools heavily rely on signal compression. It has never been analyzed how this compression affects a speaker’s persuasive and overall charismatic impact. Our study addresses this gap for the audio signal. A perception experiment was carried out in which listeners rated short stimulus utterances with systematically varied compression rates and techniques. The scalar ratings concerned a set of charismatic speaker attributes. Results show that the applied audio compression significantly influences the assessment of a speaker’s charismatic impact and that, particularly female speakers seem to be systematically disadvantaged by audio compression rates and techniques. Their charismatic impact decreases over a larger range of different codecs; and this decrease is additionally also more strongly pronounced than for male speakers. We discuss these findings with respect to two possible explanations. The first explanation is signal-based: audio compression codecs could be generally optimized for male speech and, thus, degrade female speech more (particularly in terms of charisma-associated features). Alternatively, the explanation is in the ears of the listeners who are less forgiving of signal degradation when rating female speakers’ charisma.

Phonetic research on the prosodic sources of perceived charisma has taken a big step towards making a speaker’s tone-of-voice a tangible, quantifiable, and trainable matter. However, the tone-of-voice includes a complex bundle of acoustic features, and a lot of parameters have not even been looked at so far. Moreover, all previous studies focused on political or religious leaders and left aside the large field of managers and CEOs in the world of business. These are the two research gaps addressed in the present study. An acoustic analysis of about 1,350 prosodic phrases from keynotes given by a more charismatic CEO (Steve Jobs) and a less charismatic CEO (Mark Zuckerberg) suggests that the same tone-of-voice settings that make political or religious leaders sound more charismatic also work for business speakers. In addition, results point to further charisma-relevant acoustic parameters related to rhythm, emphasis, pausing, and voice quality - as well as to audience type as a significant context factor. The findings are discussed with respect to implications for future perception-oriented studies and perspectives for a computer-based measurement, assessment, and training of a charismatic tone of voice.

Abstract In normal modally voiced utterances, voiceless fricatives like [s], [ʃ], [f], and [x] vary such that their aperiodic pitch impressions mirror the pitch level of the adjacent F0 contour. For instance, if the F0 contour creates a high or low pitch context, then the aperiodic pitch impression of the fricative in this context will also be high or low. This context-matching effect has been termed “segmental intonation”. While there is accumulating evidence for segmental intonation in speech production, less is known about if and how segmental intonation is actually integrated in the perception of utterance tunes. This question is addressed here in a perception experiment in which listeners identified target words ending in either [ʃ] or [s]. The two sibilants inherently create low or high aperiodic pitch impressions in listeners due to their characteristically different spectral energy distributions. The sibilants were preceded by high or low F0 contexts in the target words. Results show a clear F0-context effect. The context effect triggered more [ʃ] identifications in high-F0 and/or more [s] identifications in low-F0 contexts. The effect was larger for sibilants that were less clearly identifiable as either /ʃ/ or /s/. The effect represents strong supporting evidence that listeners in fact perceive the segmental intonation of fricatives and integrate its aperiodic pitch with the F0-based pitch when perceiving utterance intonation. Thus, the term “segmental intonation” is perceptually appropriate. Furthermore, the results are discussed with respect to reaction-time measurements and an additional effect of the quality of the adjacent vowel phoneme on sibilant identification.

Perceived charisma is an important success factor in professional life. However, women are worse than men in conveying physical charisma signals while at the same time having to perform better than men in order to be perceived equally charismatic. Speech prosody probably contains the most influential charisma signals. We have developed a system called “Pascal” that analyzes and assesses on objective acoustic grounds how well-speakers employ their prosodic charisma parameters. Pascal is used for charismatic-speech training in 12-weeks and 4-h courses on entrepreneurship and leadership. Comparing the prosodic-charisma scores for a total of 72 participants at the beginning and end of these two course types showed that female speakers start with significantly lower prosodic-charisma scores than male speakers. However, at the end of the 4-h course, female speakers can catch up with their male counterparts in terms of prosodic charisma. At the end of the 12-weeks courses, male speakers keep their lead, but female speakers are able to significantly reduce the prosodic charisma gap to male speakers. Since leadership and entrepreneurship are still male-dominated domains, our results can be seen as an encouragement for women to attend prosodic charisma training. Furthermore, these courses require a gender-specific design as we found men to improve mainly in F0 parameters and women in duration and phonation parameters.

Abstract. Introduction and Objectives:. There have, yet, been only few attempts to phonetically characterize the vocalizations of pain, although there is wide agreement that moaning, groaning, or other nonverbal utterance can be indicative of pain. We studied the production of vowels “u,” “a,” “i”, and “schwa” (central vowel, sounding like a darker “e” as in hesitations like “ehm”)—as experimental approximations to natural vocalizations. Methods:. In 50 students vowel production and self-report ratings were assessed during painful and nonpainful heat stimulation (hot water immersion) as well as during baseline (no-stimulation). The phonetic parameters extracted were pitch (mean F0), phonatory fluctuations (range F0) and loudness (acoustic energy level). Results:. Only for the vowels “u” and “schwa,” which might be considered best approximations to moaning and groaning, did pitch and loudness increase during pain. Furthermore, changes from nonpainful to painful stimulations in these parameters also significantly predicted concurrent changes in pain ratings. Conclusion:. Vocalization characteristics of pain seem to be best described by an increase in pitch and in loudness. Future studies using more specific and comprehensive phonetic analyses will surely help to provide an even more precise characterization of vocalizations because of pain.

Taking up anecdotal evidence, our general research aim is to investigate and to quantify the phonetic characteristics of Low German in different Northern German regions on the basis of detailed acoustic and auditory analyses. In the initial pilot study presented here, we focus on phonologically long vowels. The analyses are based on a sample of long-vowel tokens, which were produced by 18 Northern German speakers in spontaneous translations of the ‘Wenker’ sentences. The speakers had comparable dialectal competences, but came from different regions of Northern Germany, i. e. Schleswig, Holstein, Dithmarschen, Ostfriedland, Mecklenburg-Vorpommern, or Nordbrandenburg. The selected vowel tokens occurred in contexts that were phonetically controlled in terms of both consonantal coarticulation and prosodic structure. The acoustic analysis included measuring durations, formant frequencies (F1-F3) and intonation characteristics (pitch-accent F0 patterns). The auditory analysis was made by narrow phonetic transcriptions. The results of the two analyses agree in showing clear regional differences. They concern the distributions of the long vowels within the vowel space (i.e. the vowel qualities, their stabilities and phonetic distances to each other) as well as the pitch-accent intonation patterns that co-occur with the long vowels. Differences in vowel duration were not found. Nordbrandenburg and Schleswig are characterized by a wide spectrum of monophthongal long-vowel qualities. In contrast, the long vowels in Holstein, Mecklenburg-Vorpommern and Ostfriesland show less diverse quality differences in the vowel centre. However, overall the phonetic diversity is still there in terms of diphthongizations that start or end at very different qualities. The long vowels of Dithmarschen combine the two characteristics, i.e. diphthongal qualities with relatively large differences in the vowel centre. As regards the intonation patterns across the vowels, we found that Dithmarschen and Holstein are both characterized by rising-falling pitch-accent peaks, but with different alignments relative to the vowel boundaries. The pitch-accent intonations of our speakers from Ostfriesland also rose and fell across the vowel. However, unlike in all other regions they additionally showed a striking F0 shape with a long high plateau in between the rising and falling movements. Our results are discussed with regard to the current claims about the dialectal organization of Northern Germany.

Taking up anecdotal evidence, our general research aim is to investigate and to quantify the phonetic characteristics of Low German in different Northern German regions on the basis of detailed acoustic and auditory analyses. In the initial pilot study presented here, we focus on phonologically long vowels. The analyses are based on a sample of long-vowel tokens, which were produced by 18 Northern German speakers in spontaneous translations of the 'Wenker' sentences. The speakers had comparable dialectal competences, but came from different regions of Northern Germany, i. e. Schleswig, Holstein, Dithmarschen, Ostfriedland, Mecklenburg-Vorpommern, or Nordbrandenburg. The selected vowel tokens occurred in contexts that were phonetically controlled in terms of both consonantal coarticulation and prosodic structure. The acoustic analysis included measuring durations, formant frequencies (F1-F3) and intonation characteristics (pitch-accent F0 patterns). The auditory analysis was made by narrow phonetic transcriptions. The results of the two analyses agree in showing clear regional differences. They concern the distributions of the long vowels within the vowel space (i.e. the vowel qualities, their stabilities and phonetic distances to each other) as well as the pitch-accent intonation patterns that co-occur with the long vowels. Differences in vowel duration were not found. Nordbrandenburg and Schleswig are characterized by a wide spectrum of monophthongal long-vowel qualities. In contrast, the long vowels in Holstein, Mecklenburg-Vorpommern and Ostfriesland show less diverse quality differences in the vowel centre. However, overall the phonetic diversity is still there in terms of diphthongizations that start or end at very different qualities. The long vowels of Dithmarschen combine the two characteristics, i.e. diphthongal qualities with relatively large differences in the vowel centre. As regards the intonation patterns across the vowels, we found that Dithmarschen and Holstein are both characterized by rising-falling pitch-accent peaks, but with different alignments relative to the vowel boundaries. The pitch-accent intonations of our speakers from Ostfriesland also rose and fell across the vowel. However, unlike in all other regions they additionally showed a striking F0 shape with a long high plateau in between the rising and falling movements. Our results are discussed with regard to the current claims about the dialectal organization of Northern Germany.