US Patent 7681690 Noise abatement device for a pneumatic tool

Noise-abatement devices are provided for a pneumatic tool that can include a housing having a first end and a second end. An expansion chamber is defined within the expansion chamber. At least one tube is located at least partially within the expansion chamber in which the tube has at least a perforated portion, and an outlet defined therein. The device also includes a port outlet in fluid communication with the expansion chamber in which the port outlet and the outlet are located near the second end of the housing.