A system for ablating tissue includes a catheter having an elongate body, with at least one ablation element (e.g., RF electrode) and at least one acoustic transducer located within the body's tip region. The transducer receives acoustic signals from proximate the tip region. The system also includes a monitoring unit coupled to the transducer to interpret the received acoustic signals as data regarding at least one therapeutic parameter (e.g., pre-pop detection, lesion making progress, tissue interface detection, tissue contact force, tissue contact establishment, bubble spatial distribution, bubble depth, bubble size, bubble size distribution, tissue interface distance, tissue interface position, tissue attenuation, tissue thickness, lesion spectral fingerprint). The monitoring unit is operable to provide feedback to a practitioner, such as graphical, audible, and/or haptic output of sensed data, and may also be operable to control operation of the at least one ablation element in response thereto.