This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Equalloudness contours comparison with RobinsonDadson curves.svg RobinsonDadson equal loudness curves Transferred from org en by SreeBot Lindosland talk fullurl Special Listfiles Lindosland Uploads Graphic created by lindosland Nov using OpenOffice Draw Lindosland at en other versions Lindosland Original upload log page