The acoustic near-field measurement of aye-ayes’ biological auditory system utilizing a biomimetic robotic tap-scanning

Abstract

The aye-aye (Daubentonia madagascariensis) is best known for its unique acoustic-based foraging behavior called 'tap-scanning' or 'percussive foraging'. The tap-scanning is a unique behavior allowing aye-aye to locate small cavities beneath tree bark and extract wood-boring larvae from it. The tap-scanning requires the animal auditory system to have exceptional acoustic near-field sensitivity. This paper has experimentally investigated the effects of external pinna in the acoustic sensing and detection capabilities of aye-ayes. To experimentally evaluate the effects of external ear (pinna) of the aye-aye, the tap-scanning process was simulated using a robotic arm. A pinna was 3D printed using a CT scan obtained from a carcass. The pinna's effect on the acoustic near-field has been evaluated in time and frequency domains for simulated tap-scanning with the pinna in upright and cupped positions. This idea originates from behavioral observations of the aye-aye using its ears in this way. The results suggest that the aye-aye can substantially enhance its acoustic near-field sensitivity through a cupped conformation during tap-scanning. Three phenomena contribute to this substantial enhancement of the acoustic near-field: (i) a considerable increase in the signal-to-noise ratio, (ii) the creation of a focal area and potentially a focal point to increase the spatial resolution, and (iii) an increase in the receiver peak frequency by changing near-field beam pattern for higher frequencies that can result in greater sensitivity due to a smaller wavelength.

Bio-Inspired Robotic Tap Testing: An Innovative Approach for Nondestructive Testing of Wooden Structures

“…The authors have designed an instrumented tap test system inspired by the tap scanning behaviour of aye-ayes, which creates repeatable mechanical impacts. In their initial study [39], they introduced a biomimetic robotic tap-scanning system to measure the acoustic near-field of the aye-aye's biological auditory system, gaining insight into how it processes sound and uses this information to locate prey. Another study, investigated how the ear canal's shape and their morphological features affect the aye-aye's sensitivity to sound in different frequency ranges [40], concluding that their ear canal is uniquely adapted to enhance hearing sensitivity, especially in the higher frequency range.…”

Enhancing biomimetic design of tap scanning sensors through high-resolution thermal camera-based behavioral studies

“…Without proper training and expertise, there is a risk of misinterpreting the results and overlooking potential defects. 11 To address this limitation, an alternative approach inspired by nature's efficiency and objectivity in signal analysis could offer a promising solution. By drawing inspiration from biological systems and their innate ability to discern subtle cues and patterns, a bio-inspired tap testing method could enhance the objectivity of signal analysis, mitigating the challenges associated with traditional approaches.…”

“…By drawing inspiration from biological systems and their innate ability to discern subtle cues and patterns, a bio-inspired tap testing method could enhance the objectivity of signal analysis, mitigating the challenges associated with traditional approaches. 12,13 This research aims to advance behavioral studies to refine the methods used to develop a bio-mimetic taptesting sensor. 9,10 To achieve this goal, a specialized enclosure with an attached foraging box was designed to facilitate interaction and tapping behavior by the aye-aye, thereby aiding in cavity localization.…”

Design for the active arm system in automotive collision-test dummies

“…During an automobile collision, the active arms of a dummy can be characterized as a nonlinear dynamic system. When exposed to uncertain external disturbances, the precision of the endpoint position of the arm may deviate considerably [7][8][9][10].…”