Excavation with a tunnel boring machine (TBM) generates vibrations that can potentially damage nearby buildings, disrupt sensitive equipment, and disturb residents, particularly in urban environments. Quantifying the vibration energy emitted by the TBM is therefore essential for assessing structural responses and mitigating impacts. To address this challenge, two experimental campaigns were conducted in France across distinct geotechnical contexts. Vibration measurements were collected at the surface, within the soil using borehole sensors placed 2 m from the TBM, and inside the TBM itself. A novel signal processing methodology was applied to analyze the amplitude of particle velocities and the frequency content, identifying the most energetic frequency bands. The findings confirmed reduced vibration levels in the ground and validated surface measurements. These experiments provided valuable insights into the vibration source characteristics and their frequency ranges, enhancing our understanding of vibration propagation and distribution during excavation phase.