PROSODIC FEATURES OF A CHARISMATIC LECTURER: CASE STUDY

The perception of a lecturer by the audience depends not only on the content of their presentation but also on the characteristics of their vocal delivery. Lecturer charisma is one of the key factors in successful interaction with the audience, influencing students’ motivation and the quality of material retention. In recent years, there has been growing interest in studying prosodic characteristics associated with charisma, such as intonation, timbre, volume, and speech rate

A notable study by A. Rosenberg and J. Hirschberg, based on perceptual and acoustic experiments, identified acoustic cues of charisma in political discourse. It was noted that charismatic speakers are distinguished by the following prosodic characteristics: a high fundamental frequency, fast speech rate, high intensity of the speech signal, and a high degree of contrast in loudness levels

However, despite the relevance of the topic, the structural aspects of prosodic parameters that create an impression of charisma in academic speech remain underexplored. This article aims to analyze the prosodic features of a charismatic lecturer’s speech in order to identify traits that contribute to the perception of charisma. The analysis conducted will provide a deeper understanding of which prosodic characteristics can enhance the perception of charisma, thereby improving educational practices.

The experimental corpus of the study consists of two lectures by the renowned linguist D. Crystal: the lecture “Is Control of English Shifting Away from British and American Native Speakers?” (2014) and the lecture “Ludic Linguistics: the Missing Link” (2001). D. Crystal is often referred to as a charismatic speaker, both in the press (Independent) and in internet blogs. We rely on this perception of the speaker in question, as such public opinion sources have been noted to be an important indicator of the perception of charisma

The total duration of the analyzed material is 15 minutes; the length of each sample is 8 and 7 minutes, respectively. In each lecture the introductory, main topic, and conclusion sections were analyzed. The primary method of analysis was acoustic analysis of prosodic characteristics using the Praat computer program

The table below presents the prosodic characteristics of a lecturer analyzed across the two lectures, given 13 years apart. It is important to note that the significant time gap suggests the potential influence of age-related factors on the speaker's vocal behavior, which we took into consideration during the comparative analysis. The conducted acoustic analysis allowed us to pinpoint prosodic traits that set the speaker apart from others, contributing to their perceived charisma and effectiveness as a public speaker. All the data retrieved is given in Table 1.

We begin the analysis of the phonetic profiles with the most indicative prosodic parameter – median F0. First, let us note that the median F0 of an adult male is known to vary between 75 and 200 Hz while the median F0 of an adult female reportedly varies between 130-300 Hz. Across the two lectures, D. Crystal showed the difference in the median F0 values of 28 Hz (132 Hz and 104 Hz), which may be due to the influence of the age factor. However, despite this decrease in pitch, the median F0 ranging from 104 Hz to 132 Hz, is indicative of a low male voice. The finding is consistent with the previous studies showing that the use of low registers is a key feature of academic speech

In light of previous research on charisma and the reports on the existing link between charismatic speakers and greater prosodic variation in their speech, we are particularly interested in the signs of prosodic contrast in D. Crystal speech. In both lectures, D. Crystal demonstrates a consistently wide range for a male voice (33 semitones, with the average value being 22 semitones

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). At the same time, we also note a high level of standard deviation (72 Hz and 70 Hz), which indicates the presence of prosodic contrasts and frequent transitions between high and low tones. The aforementioned contrasts in the pitch contour have been observed in Fig. 1.

Figure 1 - The pitch contour of the speaker’s voice in Lecture 1

DOI:10.60797/RULB.2024.59.20.2

Prosodic contrast is also manifested in the intensity of the sound signal. The sound signal in all samples can be described as having a median loudness level, but the interval between minimum and maximum values indicates high variability in volume levels, which is also a characteristic of charisma. The speech rate of the analyzed lecturer is average. The ASD (197 ms and 228 ms) corresponds to average statistical data, and the high pause density contributes to better understanding of the material.

The results of the theoretical and empirical research presented in the article indicate common prosodic features associated with speaker charisma across different types of professional speech. In political discourse, business leader speeches, and lecturer speeches, the following charismatic traits are highlighted: high F0 value dispersion and a high degree of contrast in volume levels. Thus, prosodic contrast can be considered a universal feature of charisma. The speech tempo is average in business leaders' speech and high in political discourse. The F0 is average in lecturers' speech and high in the speech of business leaders and politicians.

Future research may focus on conducting a perceptual analysis, identifying non-charismatic lecturers, and comparing their speech behavior with that of charismatic lecturers. Expanding the experimental corpus and comparing lecturers from different gender and age groups will also allow for analyzing the values of voice quality parameters, which remain as constant as possible for a single individual within a single phonostyle. Examining these aspects will allow for a deeper understanding of the mechanisms of interaction between a lecturer and the audience, as well as the prospects for optimizing the educational process.

A more detailed study of charisma is highly relevant in the era of soft skills and is essential for lecturers who want to improve their interaction with the audience, as well as for those teaching foreign languages to help learners confidently structure their public speaking.