Biology subjects

Pouw, W.

Publications and source records attributed to Pouw, W..

5 recordsLinked to original sources

bioRxiv2026

When communication fails, physical effort increases but not to greater effect

Successful communication depends not just on what we say but also on how we repair it when understanding breaks down. People routinely respond to misunderstanding by gesturing more or speaking louder. Yet whether these responses actually reflect measurable bodily effort, and whether it helps communication, has not yet been directly tested. Extending the hypo- and hyper-articulation accounts to whole-body multimodal communication we ask: does regaining understanding require increased physical effort, and does that effort improve communicative outcomes? In a pre-registered biomechanical study, 61 pairs of participants conveyed concepts without conventionalized language, using gestures, vocalizations, or both, and repaired failed attempts. We measured communicative effort by capturing arm torque change (upper-limb effort), vocal amplitude (vocal effort), and postural adjustments (postural effort). Using Bayesian hierarchical models, we show that repair increases physical effort across all three measurements, but that performers communicate more over time rather than more forcefully at any particular moment in time. Upper-limb effort scale with the degree of misunderstanding but effort overall does not predict whether communication succeeds. We suggest that communicative effort on the level we measured here functions as an index of continued commitment rather than a mechanism for repairing misunderstanding.

physiology↗

bioRxiv2025

Dissociating mechanisms of heart-voice coupling

In a landmark paper in JASA, Orlikoff & Baken (1989a) demonstrated that the heartbeat carries through acoustic features of the human voice. Heart-voice coupling questions how vocal control is functionally regulated and has many potential engineering applications to extract heart rate from the human voice. However, laboratory phonology and bioacoustics seem to have forgotten about the phenomenon, such that its physiological underpinnings have been left unexplained. The current contribution showed that vocal acoustics contain signatures of the heartbeat as originally reported by Orlikoff & Baken (1989a). More specifically, the steady-state vowel vocalizations of 17 participants were analysed and a significant relationship between the vocal acoustic envelope and the cardiac activity (ECG) was found. Furthermore, two empirical tests were conducted to discriminate between vocal fold (vascularization) and pulmonary (heart-lung interaction) mechanisms of heart-voice coupling. In addition to a stable heart-voice coupling, a significant heart-expiration coupling during conditions of silent expiration was also found. Since the vocal folds are abducted during expiration, this result demonstrated that pulmonary mechanisms that modulate expiratory flow must be involved in heart-voice coupling. It is speculated that the hearts rhythm may be a weakly coupled pattern generator that possibly shaped the evolution of vocal and speech production.

neuroscience↗

bioRxiv2024

Arm movements increase acoustic markers of expiratory flow

The gesture-speech physics theory suggests that there are biomechanical interactions of the voice with the whole body, driving speech to align fluctuations in loudness and F0 with upper-limb movement. This exploratory study offers a possible falsification of the gesture-speech physics theory, which would predict effects of upper-limb movement on voice as well as respiration. We therefore investigate co-movement expiration. Seventeen participants were asked to produce a continuous exhalation for several seconds. After 3s, they execute one of five within-subject movement conditions with their arm with and without a wrist weight (no movement, elbow flexion, elbow extension, internal arm rotation, external arm rotation). We analyzed the smoothed amplitude envelope of the acoustic signal in relation to arm movement. Compared to no movement, all four movements lead to higher positive peaks in the amplitude peaks, while weight did not influence the amplitude. We also found that across movement conditions, positive amplitude peaks are structurally timed relative to peaks in kine-matics (speed, acceleration). We conclude that the reason why upper-limb movements affect voice loudness is still best understood through gesture-speech physics theory, where upper-limb movements affect the voice directly by modulating sub-glottal pressures. Multimodal prosody is therefore partly literally embodied.

neuroscience↗

bioRxiv2023

The human voice aligns with whole-body kinetics

Humans often vocalize while concurrently gesturing with their hands. Fluctuations in the intensity and tone of the voice have been shown to synchronize with gestural upper limb movement. This research provides direct evidence that interactions between arm movements and postural muscle activity cause these voicing fluctuations. We show that specific muscles (e.g., pectoralis major, erector spinae), associated with upper limb movement and their postural anticipations, are especially likely to interact with the voice. Adding mass to the upper limb increased this interaction. Ground-reaction forces were also found to relate to postural muscles, and these measurements also directly covaried with fluctuations in the voice during some movement conditions. These results show that the voice co-patterns with whole-body kinetics, i.e. forces. We thereby go beyond kinematic analyses in studying interactions between gesturing and vocalization, invoking several implications for biomechanical modeling. We conclude that human voicing has evolved in a dynamical interaction with the whole-body motor system.

neuroscience↗

bioRxiv2023

Postural and muscular effects of upper-limb movements on voicing

Voice production can be a whole-body affair: Upper limb movements physically impact the voice in steady-state vocalization, speaking, and singing. This is supposedly due to biomechanical impulses on the chest-wall, affecting subglottal pressure. Unveiling such biomechanics is important, as humans gesture with their hands in a synchronized way with speaking. Here we assess biomechanical interactions between arm movements and the voice, by measurement of key (respiratory-related) muscles with electromyography (EMG) during different types of upper limb movement while measuring the bodys center of mass. We show that gesture-related muscle activations scale with positive peaks in the voices amplitude. Some of these muscles also strongly associate with changes in the center mass, confirming that gesture-vocal coupling partly arises due to posture-related muscle activity. If replicated, these results suggest an evolutionary ancient gesture-vocal connection at the level of biomechanics. These preliminary results will support a pre-registration of analyses for a larger-scale confirmatory study.

neuroscience↗