This paper deals with vibration and noise analysis of a gearbox to detect various gear faults. An attempt has been made to compare the effectiveness of acoustic and vibration analysis for detecting faults in the gearbox. Experiments were performed on a single-stage spur gearbox. Sound pressure and vibration signal were recorded. On gear teeth, three different types of defects such as missing tooth, profile error, and crack in the root were introduced. The analysis was conducted by evaluating signals of defective condition against a healthy condition. The study found that any gearbox faults can be identified using the sound pressure spectrum analysis. These findings show that the proposed acoustic method offers a good alternative to traditional vibration analysis for identification of gear faults.