@article {526,
	title = {The uncanny valley effect for prosody},
	year = {2023},
	publisher = {Nederlandse Vereniging voor Fonetische Wetenschappen},
	address = {Utrecht, The Netherlands},
	abstract = {The incorporation of human-like traits into intelligent verbal agents (IVAs) can strengthen their appeal as users are inclined to anthropomorphize technology. Nevertheless, non-human objects with close-to-human characteristics can evoke the uncanny valley effect (UVE), a feeling of eeriness. This study investigated whether very human-like prosody used by IVAs can evoke a UVE, looking at perceived eeriness, robomorphism, anthropomorphism and trust in/of IVAs. Two experiments were conducted in which participants (N = 88) listened to a virtual museum guide. The guide{\textquoteright}s voice was a human voice, the pitch of which was manipulated to sound more robotic, by reducing the variation around the declination over the utterance (first experiment) or around the average (second experiment). The reduction was 0\% (human), 33\%, 66\% or 100\% (most robotic); participants listened to each level once. There was a linear relationship between degree of prosody manipulation and participants{\textquoteright} perceptions on the variables mentioned above, in the expected directions (experiment 1: 0.31 < |b| < 0.57,  p < 0.001; experiment 2: 0.27 < |b| < 0.74, p < 0.001), but no evidence of a UVE. However, a few individuals did show a clear and consistent UVE, the significance of which cannot be estimated as each level was presented only once. A follow-up study using a finer-grained difference and more measurements per participants is underway; results will be discussed. This study{\textquoteright}s insights can contribute to better design and implementation of IVAs by tackling potentially unfavorable emotional and behavioral reactions to human-like voices. },
	keywords = {Anthropomorphism, Human-Robot Interaction, Intelligent Virtual Assistants, Prosody, Uncanny Valley Effect},
	author = {Alipour, Ahdiyeh and Tom Lentz}
}
@article {460,
	title = {Perception-production relationships in weighting phonetic cues of vowel contrasts},
	year = {2019},
	publisher = {Nederlandse Vereniging voor Fonetische Wetenschappen},
	address = {Amsterdam, The Netherlands},
	abstract = {The present study set out to investigate phonetic cue weighting for phonological contrasts in production and perception. Specifically, we investigated the effect of normalization for individual perceptual acuity on the correlations between perceptual cue weighting and produced contrast. Our hypothesis was that production and perception are balanced based on just noticeable difference (JND) units.

Participants were 47 young adult speakers of Dutch (age 19-29). The stimuli consisted of the Dutch /ɑ/-/a/ vowel contrast (which differs both in spectral properties and duration). Measurements comprised JND{\textquoteright}s for spectral and durational differences, perceptual cue-weighting, and produced differences in formants and duration. Cue-weighting and produced contrast were converted into a non-normalized- (value_formants/value_formants+value_duration) and a JND-normalized ratio ((value_formants/JND_formants)/(value_formants/JND_formants)+(value_duration/JND_duration)).

The results showed a significant effect of normalization and a pattern of negative correlations (if a cue is more important in perception, it is expressed less in production) turned into a pattern of positive correlations after JND-normalization. These findings suggest that production and perception are balanced based on relative perceptual acuity. The driving mechanism thus could be summarized as egocentrism or subjective balance. If speakers are perceptually more sensitive to changes on a dimension, they express objectively smaller differences on that dimension.
},
	author = {Hayo Terband and Tom Lentz}
}
@article {14,
	title = {Articulatory control parameters of phonological contrasts: the case of cue-weighting for Dutch /ɑ/ - /a/},
	year = {2016},
	publisher = {Nederlandse Vereniging voor Fonetische Wetenschappen},
	address = {Utrecht, Nederland},
	abstract = {<p>Speech-language acquisition involves learning the speech sounds of the language at hand as well as which acoustic cues are relevant to differentiate them. For example, the Dutch vowels /ɑ/ and /a/ in the words {\textquoteright}man{\textquoteright} (man) and {\textquoteright}maan{\textquoteright} (moon) differ both in their spectral properties (F1 and F2 are both higher for /a/) and in duration (longer for /a/). Perception experiments indicate that the way in which different perceptual cues are being combined and weighted is language specific, however, there are large individual differences in cue weighting within language groups (Escudero, Benders, \&amp; Lipsky, 2009). Furthermore, the different perceptual cues are not entirely independent from a speech acoustics point of view, meaning that one of the cues could play a more prominent role underneath. The present study combines measurements of perceptual weighting of acoustic cues for the Dutch /ɑ/ - /a/ vowel contrast with measurements of perceptual acuity for spectral and durational differences and measurements of the production of the vowel contrast to unravel (1) what exactly influences how perceptual cues are being weighted, and (2) which cue is actively being manipulated by speakers. 45 young adult speakers of Dutch (age 19-29) participated in the study. Data analysis is currently underway; detailed results will be available at the symposium. References Escudero, P., Benders, T., \&amp; Lipski, S. C. (2009). Native, non-native and L2 perceptual cue weighting for Dutch vowels: The case of Dutch, German, and Spanish listeners. Journal of Phonetics, 37(4), 452-465.</p>
},
	author = {Hayo Terband and Lydia Bax and Peter Hart and Manou van Montfort and Sapna Sehgal and Laura Smorenburg and Fleur Versteeg and Tom Lentz}
}
