Background: Fully implantable active middle ear implants require implantable sensors to replace external microphones. A recently proposed piezoelectric sensor for ossicular coupling is promising, but data on anatomical feasibility and the impact of coupling mechanics on sensor performance and feedback are limited. Objective: To assess the anatomical feasibility of ossicular coupling sites and evaluate sensor sensitivity and feedback for alternative coupling strategies using a piezoelectric sensor. Methods: Ear morphology was assessed in a retrospective, single center analysis of 101 ears from 99 patients undergoing Vibrant Soundbridge implantation. Temporal bone experiments (n = 26) yielded comparative measurements of sensor sensitivity and Floating Mass Transducer (FMT)-induced feedback for a piezoelectric sensor prototype coupled at the umbo and incudostapedial joint. In umbo coupling, the sensor was braced against the promontory using custom-made spacers. Results: The umbo was feasible in 71 % of ears, whereas an intact incudostapedial joint was present in 30 %, mainly due to prior surgery. In temporal bones with intact ossicular chains, umbo coupling showed sensitivity comparable to incudostapedial coupling, with most deviations within ±10 dB across 0.5–4 kHz. Spacer stiffness and contact force influenced sensitivity, with low pretension (∼10 mN) yielding the most stable responses. FMT-induced feedback at the umbo was comparable to or lower than incudostapedial coupling. Conclusion: The umbo is a feasible and robust coupling site for implantable piezoelectric sensors. Spacer-mediated coupling accommodates anatomical variability while maintaining sensitivity and favorable feedback, supporting its use as an alternative to incudostapedial joint placement.