Express Paper
Towards Vibrotactile Transducer Characterization
AES Convention 155 · Paper 135 · October 2023
Abstract
Vibrotactile transducers (VTTs) are used in vibroacoustic applications for enhancing perception of low frequencies. These are used in conjunction with traditional audio transducers for a combined auditory and physical experience of sound and vibration perception, for applications ranging from music production to video gaming.
Audio transducers can be optimally selected taking into account audio content, environment and transducer characteristics required for the desired application. Optimal selection for VTTs additionally requires taking into account variations resulting from coupling of varying external mechanical loads at different power levels. The traditional method for measuring total harmonic distortion (THD) to capture harmonic content, while useful in the audio domain, does not factor in varying external mechanical loads and thus is not appropriate for judging performance of VTTs. Unlike traditional transducers, VTTs operate in highly non-linear modes in most applications resulting in over 100% estimates for THDs. Thus, we introduce a new metric called transducer harmonics moment (THM), which considers the significance of harmonics with respect to their frequency and amplitude within a selected bandwidth. This results in more useful estimates compared to traditional THD in the vibrotactile domain.
