Audiobooks are today the format in which it is expected that there will be more growth in the coming years. In the last five years, in the United States, there has been a significant increase in popularity that has led to a spectacular increase in sales. However, so far there have been no studies that analyze the most effective sound design in an audiobook to improve audience perception and cognitive processing. The sound design of an audiobook may be very important for the success of this kind of products. In this sense, this study aims to analyze what is the sound format that stimulates to a greater extent the creation of mental images in the listeners, which allows them to get more involved in the story, gives them more attention, motivation, emotional activation, and favors their recall. To do this, an experiment will be designed where a sample of subjects who will listen to fragments of audiobooks with different formats (only voice, different voices, voice and music, voice and sound effects). While listening to the audiobooks, their physiological response to the audio stimulus will be measured: attention, arousal, and emotional reaction. In addition, they will fill out scales to measure the creation of mental images and the involvement. Finally, a memory test will be performed to measure the recall of the story.