Within the trilogy, The Voyage of the Dawn Treader is often the "top" search result for dual audio. Why? Because of its high dialogue-to-action ratio. The scenes with Reepicheep the mouse and Eustace the dragon contain complex emotional dialogue that users want to hear in their native language without losing the original actor's emotional delivery.
If you are looking for the or radio dramas (often confused with movie downloads): the chronicles of narnia dual audio download top
Streaming services typically provide the original English audio along with various dubbed languages (e.g., Hindi, Russian, Spanish) and subtitles. Within the trilogy, The Voyage of the Dawn
For your essay, are you focusing on one specific book in the series, or the movies as a whole? Within the trilogy