No, there is no standard way to directly stream audio through telnet. However, people tried to do this using protocol extensions .
Another approach that I have seen (for example, in IRC) is for clients to recognize a special command that says: "Please play this audio file." The client will look in the configured directory for an audio file with that name, and if it is found, it will play sound. Depending on your needs, this can be a workable technique.