Beijing Higher People's Court recently made the final decision on China's first sound trademark case, ruling in favor of QQ, one of the most popular instant messaging software services, launched by Tencent in China.

The appeal court upheld the original decision and said that the signature "Di-Di-Di-Di-Di-Di" notification sound has been used by QQ for a long time and has obtained the status of being a distinguishing feature of the service provider.

Since the sound has become famous among the public in the instant messaging sphere, it has established a firm and clear connection in the public consciousness to the QQ application's functions, including online chatting as well as transferring messages, pictures and other digital documents, according to the court.

Tencent began to apply for a trademark using the sound in 2014 yet was rejected for "lacking a distinguishing feature" in 2015.

The trademark administration said the sound "Di" can be commonly found in many electric products and cannot be used to specifically distinguish the service provider.

The company said its sound is not just a simple repetition. It provided the court with a spectral catalogue, frequency spectrum and oscillogram of the sound, as well as 152 documents from the National Library of China, to prove that the QQ notification sound had been used widely and for a long time, and could serve to distinguish the service provider.