This study investigates the sound absorption characteristics of porous asphalt concrete (PAC) pavements using an impedance tube to assess noise reduction performance. It is clearly shown that an improved attenuation of sound wave energy is achieved by adjusting the air void content, aggregate gradation, and PAC pavement thickness, based on measurements of sound absorption coefficients. In addition, traffic noise measurements taken from PAC pavements in the field are compared to those taken from dense-graded asphalt concrete (DGAC), which is widely used in pavement materials.