In multimedia presentations, the combination of images and text helps students effectively acquire new knowledge. The images on the slides often represent only a portion of the spoken content (audio-and-picture information). Pictures can enhance memory retention for information presented with both audio and pictures. However, it is unclear how well students recall material that is presented solely through speech (audio-only information) when it is spoken alongside audio-and-picture information. Images can support learning when paired with matching audio; however, they also have a perceptual advantage over words, therefore, they may also distract attention from audio-only information. Especially when the number of simultaneous images increases. Therefore, this study tested whether learning efficiency for audio-only information changes with varying numbers of pictures compared to audio-and-picture information. We recruited 260 high school students (M=16 years, SD=0.874), and each student watched a 12-slide multimedia presentation. The number of content-relevant pictures per slide varied from 0 to 2. Afterward, participants answered 24 questions assessing recall of audio-and-picture and audio-only information. Results showed that students generally recalled more audio-and-picture information. The recall of audio-only information was similar for slides including zero or one picture. However, recall significantly decreased when two pictures were simultaneously presented. These findings suggest that images can effectively emphasize and teach important terms and concepts. However, to achieve the best results, it is advisable to include no more than one picture per slide. Including even two images may decrease the learning efficiency of the audio-only information.