1. A computer-implemented method for audibly indicating footnotes in text during text-to-speech processing, the method comprising: obtaining a target sentence to convert from text to speech, the target sentence including primary text and a footnote associated with the primary text; identifying a textual indicator associated with the footnote in the primary text; generating first speech data corresponding to a first portion of the primary text, the first portion preceding the textual indicator; generating second speech data corresponding to a second portion of the primary text, the second portion following the textual indicator; generating an audio tone corresponding to the textual indicator, the audio tone comprising a beeping sound; and outputting first audio including the first speech data, followed by the audio tone, then followed by the second speech data.