Music Tactalizer: A Wearable Haptic Music Player with Multi-Feature Audio-Tactile Rendering

Haptic music player wearables use vibrotactile feedback to improve the immersion and quality of the music listening experience. The most common rendering approach is transducing the audio into tactile signals, but the human tactile perception capacity requires a frequency limit of 1 kHz, heavily limiting the communication of music features. In this study, we introduce the Music Tactalizer, a wearable haptic music player that enriches the music listening experience by embedding pitch, rhythm, melody, and timbre information through audio-tactile mapping. The algorithm extracts the music features and converts them to tactile signals using digital signal processing. Through a mobile app that provides synchronized audio and visual feedback, the tactile signals are transmitted to a wearable using Bluetooth Low Energy to deliver vibrotactile feedback to the user's fingertips. The generated tactile signals were validated using mean average error (MAE), dynamic time warping (DTW) distance, and accuracy, yielding normalized averages of 0.1240 MAE and 0.1392 DTW distance, and a 78.24% rhythmic pattern accuracy. The Music Tactalizer can communicate multiple musical features at an auditory frequency range while retaining most of the original audio signal's characteristics. Future research can improve the quantitative results or explore other methods and applications.