Auditory-Tactile Congruence for Synthesis of Adaptive Pain Expressions in RoboPatients

TL;DR

This study explores how auditory feedback, specifically pitch and amplitude, can be modulated to create more realistic and perceptually coherent pain expressions in robotic patients, enhancing training and evaluation of clinicians.

Contribution

It introduces a novel framework for synthesizing adaptive pain vocalizations based on tactile input, emphasizing the importance of auditory-tactile congruence in robotic pain simulation.

Findings

Pitch significantly influences perceived pain congruence.

Increased palpation force correlates with higher perceived pain.

Amplitude also affects perception but less strongly than pitch.

Abstract

Misdiagnosis can result in delayed treatment and patient harm. Robotic patient simulators (robopatients) provide a controlled framework for training and evaluating clinicians in rare and complex cases. We investigate auditory tactile congruence in the synthesis of adaptive vocal pain expressions for robopatients. The system generates pain vocalizations in response to tactile stimuli applied during abdominal palpation. Haptic input is captured through an abdominal phantom and processed using an internal palpation-to-pain mapping model that drives acoustic output. To evaluate perceptual congruence between palpation force and synthesized pain expressions, we conducted a study comprising 7,680 trials with 20 participants. Participants rated perceived pain intensity based solely on auditory feedback. We analyzed the influence of acoustic parameters on agreement between applied force and perceived pain. Results indicate that amplitude and pitch significantly affect perceptual agreement, independent of pain sound category. Increased palpation force was associated with higher agreement ratings, consistent with psychophysical scaling effects. Among the tested acoustic features, pitch exerted a stronger influence than amplitude on perceived congruence. These findings demonstrate that modulation of pitch and amplitude is critical for achieving perceptually coherent auditory tactile mappings in robotic pain simulation. The proposed framework supports the development of high fidelity robotic patient simulators and provides a platform for studying multidimensional representations of pain in embodied robotic systems.