adj.impossible or difficult to perceive by the mind or senses

"color is unperceivable to the touch"

同義詞：imperceptible

Copyright protection of digital images by embedded unperceivable marks
QoE-Based Cross-Layer Optimization of Wireless Video with Unperceivable Temporal Video Quality Fluctuation
Perceiving by proxy: Effect-based action control with unperceivable effects
Unperceivable noise to active light touch effects on fast postural sway.
Might outdoor heat stress be considered a proxy for the unperceivable effect of the ultraviolet-induced risk of erythema in Florence?
QoE-based resource reservation for unperceivable video quality fluctuation during Handover in LTE
QoE-based resource reservation for unperceivable video quality fluctuation during Handover in LTE
QoE-Based Cross-Layer Optimization of Wireless Video with Unperceivable Temporal Video Quality Fluctuation
iDAF-drum: Supporting Everyday Practice of Drum by Adding an Unperceivable Factor
Dream depictions of the 'unperceivable' object of emotional loss