Reading is often an important source of input for language learners, but learning vocabulary through reading can be a slow process. Glossing has the potential to increase the speed and accuracy with which learners incorporate new words into their vocabulary by providing context-specific information about target words. Although there are many studies on glossing, few studies have examined the usefulness of audio versus textual glosses as aids in acquiring vocabulary while reading foreign language texts. This study sought to understand the effect of gloss condition (audio-gloss, textual-gloss, no-gloss) on incidental vocabulary acquisition while reading for language learning purposes. A total of 11 undergraduate participants read a text in Spanish in either the unglossed (control), text-gloss, or audio-gloss condition. They completed both a vocabulary pre-test and post-test consisting of a modified version of the Vocabulary Knowledge Scale (VKS) to measure vocabulary growth through reading. Results showed that all participants were able to acquire target vocabulary through reading. The higher means of the audio and text-gloss groups, though not statistically significant, suggest that a future study with a larger sample size, may provide more insight about the relative advantage of audio versus textual glosses for vocabulary learning through reading in a foreign language.