No. The video description option must be activated by the user. For analog television (NSTC), an alternate audio channel, known as SAP (Secondary Audio Program), is used to send the audio with the video description. The viewer must select the audio they wish to hear. The choices are either the main audio without description or the SAP audio with description.
It is possible to send up to four audio channels per program using digital television. One of these channels is used to send the video description audio.