Conclusion: Vibrant Soundbridge (VSB) application to the middle ear windows yields better functional outcomes than conventional hearing aids. However, speech discrimination scores obtained with VSB and conventional hearing aids are similar. Objective: To assess audiological outcomes of round and oval window applications of VSB in comparison with conventional hearing aids. Methods: Nineteen adult patients were included in the study. The patients had mild to moderate, moderate or moderate to profound conductive or mixed hearing loss. During surgery the floating mass transducer (FMT) was placed on the round (n = 14) or oval (n = 5) window. After the surgery, audiometric evaluation and free field audiometric evaluation of both ears was carried out. Results: The hearing thresholds in the low frequencies were not significantly different between the conventional hearing aids and VSB. The functional gains obtained with oval and round window approaches were similar except for 500 Hz. The hearing thresholds in the mid and high frequencies were significantly better with VSB than the conventional hearing aids. The functional gain in the low frequencies was not significantly different between VSB and conventional hearing aids. The functional gain in the other frequencies was significantly better with VSB than conventional hearing aids.