The Production and Judgment of Smile Magnitude

Articulation posture influences pitch during singing imagery

Facial muscle activity contributes to singing and to articulation: in articulation, mouth shape can alter vowel identity; and in singing, facial movement correlates with pitch changes. Here, we examine whether mouth posture causally influences pitch during singing imagery. Based on perception-action theories and embodied cognition theories, we predict that mouth posture influences pitch judgments even when no overt utterances are produced. In two experiments (total N = 160), mouth posture was manipulated to resemble the articulation of either /i/ (as in English meet; retracted lips) or /o/ (as in French rose; protruded lips). Holding this mouth posture, participants were instructed to mentally "sing" given songs (which were all positive in valence) while listening with their inner ear and, afterwards, to assess the pitch of their mental chant. As predicted, compared to the o-posture, the i-posture led to higher pitch in mental singing. Thus, bodily states can shape experiential qualities, such as pitch, during imagery. This extends embodied music cognition and demonstrates a new link between language and music.

Setting the Stage for Speech Production: Infants Prefer Listening to Speech Sounds With Infant Vocal Resonances

PURPOSE

Current models of speech development argue for an early link between speech production and perception in infants. Recent data show that young infants (at 4-6 months) preferentially attend to speech sounds (vowels) with infant vocal properties compared to those with adult vocal properties, suggesting the presence of special "memory banks" for one's own nascent speech-like productions. This study investigated whether the vocal resonances (formants) of the infant vocal tract are sufficient to elicit this preference and whether this perceptual bias changes with age and emerging vocal production skills.

METHOD

We selectively manipulated the fundamental frequency (f₀ ) of vowels synthesized with formants specifying either an infant or adult vocal tract, and then tested the effects of those manipulations on the listening preferences of infants who were slightly older than those previously tested (at 6-8 months).

RESULTS

Unlike findings with younger infants (at 4-6 months), slightly older infants in Experiment 1 displayed a robust preference for vowels with infant formants over adult formants when f₀ was matched. The strength of this preference was also positively correlated with age among infants between 4 and 8 months. In Experiment 2, this preference favoring infant over adult formants was maintained when f₀ values were modulated.

CONCLUSIONS

Infants between 6 and 8 months of age displayed a robust and distinct preference for speech with resonances specifying a vocal tract that is similar in size and length to their own. This finding, together with data indicating that this preference is not present in younger infants and appears to increase with age, suggests that nascent knowledge of the motor schema of the vocal tract may play a role in shaping this perceptual bias, lending support to current models of speech development.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.17131805.

Mommy is only happy! Dutch mothers' realisation of speech sounds in infant-directed speech expresses emotion, not didactic intent

Exaggeration of the vowel space in infant-directed speech (IDS) is well documented for English, but not consistently replicated in other languages or for other speech-sound contrasts. A second attested, but less discussed, pattern of change in IDS is an overall rise of the formant frequencies, which may reflect an affective speaking style. The present study investigates longitudinally how Dutch mothers change their corner vowels, voiceless fricatives, and pitch when speaking to their infant at 11 and 15 months of age. In comparison to adult-directed speech (ADS), Dutch IDS has a smaller vowel space, higher second and third formant frequencies in the vowels, and a higher spectral frequency in the fricatives. The formants of the vowels and spectral frequency of the fricatives are raised more strongly for infants at 11 than at 15 months, while the pitch is more extreme in IDS to 15-month olds. These results show that enhanced positive affect is the main factor influencing Dutch mothers' realisation of speech sounds in IDS, especially to younger infants. This study provides evidence that mothers' expression of emotion in IDS can influence the realisation of speech sounds, and that the loss or gain of speech clarity may be secondary effects of affect.