Adding audio notes to PDFs can be useful for a PDF slideshow or presentation because it makes it more interesting and interactive. For students, you can record your or professor’s voice and add it to the PDF for keeping all valuable information in one place.
1. Open a PDF in PDF Reader
2. Tap the "Microphone" icon on the annotation toolbar to turn on audio recording
3. Select the PDF page and tap on where you want to place an audio note to the PDF (Or you can directly tap and hold on the location where you want to insert an audio note and tap "Sound")
4. Tap "Add here" to start recording
5. Then the audio recording pane will appear on the bottom of the screen. Tap “Done” to stop and save the audio note.
6. To play the audio, simply tap on the “Play” button.
(Note: PDF Reader works well with up to 15 minutes audio recording on a file. The PDF format is not intended for keeping large audio recordings)