File:演講『國語語調』之趙元任（二四年二月八日）.jpg

According to copyright laws of the People's Republic of China (with legal jurisdiction in the mainland only, excluding Hong Kong and Macao), amended November 11, 2020, Works of legal persons or organizations without legal personality, or service works, or audiovisual works, enter the public domain 50 years after they were first published, or if unpublished 50 years from creation. For photography works of natural persons whose copyright protection period expires before June 1, 2021 belong to the public domain. All other works of natural persons enter the public domain 50 years after the death of the creator.
According to copyright laws of Republic of China (currently with jurisdiction in Taiwan, the Penghu, Kinmen, Matsu, etc.), all photographs and cinematographic works, and all works whose copyright holder is a juristic person, enter the public domain 50 years after they were first published, or if unpublished 50 years from creation, and all other applicable works enter the public domain 50 years after the death of the creator.

This work is in the public domain in the United States, because it was in the public domain in its home country (People's Republic of China and/or Republic of China) on the URAA date (January 1, 1996 for PRC, January 1, 2002 for ROC), and it wasn't re-published for 30 days following initial publications in the U.S.