This PhD topic addresses critical challenges in the nuclear sector, such as monitoring reactors, fuels, and waste, by eliminating risks associated with drilling metal walls (leaks, contamination) while ensuring resistance to extreme environments (radiation, high temperature, pressure). It also offers applications in the medical field, particularly for implantable devices and non-invasive diagnostics. The primary objective is to develop passive acoustic telemetry systems capable of measuring physical parameters behind a metal wall without requiring electronics on the inaccessible side. Inspired by radio frequency (RF) techniques, this approach aims to overcome the limitations of current sensors, which often cannot penetrate metal barriers or require embedded electronics. The work will build on the expertise of the Systems Department in acoustic modeling, piezoelectric materials, and frequency transposition techniques, while fostering cross-disciplinary collaboration across various CEA entities, particularly in RF and MEMS domains. The expected results include novel passive acoustic telemetry techniques and associated design methods, providing a robust and innovative alternative to existing sensors. Structured in three phases (literature review, development, and experimentation), this thesis is part of a collaborative effort within the CEA, with concrete application potential in nuclear, medical, and industrial fields.