Ensuring regular movement and power transmission in gear wheels is possible with a suitable tooth profile. Although involute profiles have a structure that can provide conjugate movement in accordance with the law of gearing, transmission errors that cause vibration and noise occur due to the flexibility of the elements in the gear system under dynamic conditions. Transmission errors occur depend-ing on many parameters from production to the oil and lubrication system. In this study, the vibration and noise state generated during transmission in gears were investigated in relation to geometric parameters. In the reference gear pair as-sumption, the noise levels were evaluated for the four cases created due to the change of different geometric parameters. The effect of profile modification on vibration and noise was addressed, and optimum profile modification parameters for the reference gear pair were analyzed with KISSsoft commercial software. The effects of geometric parameters and profile modification on noise level are shown in graphs. With the application of the Tip Relief method, a significant de-crease in the noise level has been observed.