Sound acts as cinematic codes for the filmmaker to create a work of art. In the meantime, industrial documentary can bring a different experience for the audience due to its link to advertising and education. The codification process of the filmmaker and the effects and the relationship between the audience and the work have been studied in different theories, such as perception theory by Stuart Hall. In the reception analysis, the fundamental presupposition is that media texts, which are of coded meanings, do not have a fixed meaning, but are meaningful at the moment of reception by the audience. In Hall's encoding and decryption model, the encoder first presents his own account of an unprocessed social event in a meaningful discourse, and finally, the audience decodes the message.
This research, conducted in an analytical-descriptive method, involves a transition to a semiotic approach to the sounds of film to investigate its processing for meaning production for training and advertising goals. The results showed that with structural analysis of the film’s sound, the codified explicit and implicit messages can be understood. In two selected industrial documentaries made by Kamran Shirdel, the sound played a role in introducing the event, transferring the message, activating the sense, presence in the past, visual expression, characterization, personification of space, symbolization, and creating a common sense and by creating an added value on the image, in the same direction with the communicative pattern of the author and the message, has been applied in the social ground.