Distributed tactile sensing remains difficult to scale over large areas: dense sensor arrays increase wiring, cost, and fragility, while many alternatives provide limited coverage or miss fast interaction dynamics. We present Sound of Touch, an active acoustic tactile-sensing methodology that uses vibrating tensioned strings as sensing elements. The string is continuously excited electromagnetically, and a small number of pickups (contact microphones) observe spectral changes induced by contact. From short-duration audio signals, our system estimates contact location and normal force, and detects slip. To guide design and interpret the sensing mechanism, we derive a physics-based string-vibration simulator that predicts how contact position and force shift vibration modes. Experiments demonstrate millimeter-scale localization, reliable force estimation, and real-time slip detection. Our contributions are: (i) a lightweight, scalable string-based tactile sensing hardware concept for instrumenting extended robot surfaces; (ii) a physics-grounded simulation and analysis tool for contact-induced spectral shifts; and (iii) a real-time inference pipeline that maps vibration measurements to contact state.

翻译：分布式触觉感知在大面积扩展方面仍面临挑战：密集的传感器阵列会增加布线、成本和脆弱性，而许多替代方案则覆盖范围有限或无法捕捉快速交互动态。本文提出“触觉之声”，一种利用振动张紧弦作为传感元件的主动声学触觉感知方法。该弦通过电磁方式持续激励，少量拾音器（接触式麦克风）观测由接触引起的频谱变化。基于短时音频信号，我们的系统能够估计接触位置与法向力，并检测滑动。为指导设计并解释传感机理，我们推导了一个基于物理的弦振动模拟器，用于预测接触位置和力如何改变振动模态。实验证明了毫米级定位精度、可靠的力估计以及实时滑动检测能力。我们的贡献包括：（i）一种轻量化、可扩展的基于弦的触觉感知硬件概念，适用于机器人扩展表面集成；（ii）一个基于物理的接触诱发频谱偏移模拟与分析工具；（iii）一个将振动测量映射至接触状态的实时推理流程。