How to Add Voice Notes and Audio to a PDF on iPhone with Fileso

A voice note can explain a diagram, preserve spoken feedback, or add context to a page without covering it with text. Fileso lets you pin audio to a specific position in a PDF on iPhone or iPad. You can record in the editor, choose an audio file, or take the sound from a video in Photos. The saved PDF carries a Sound annotation, rather than a separate audio file that must be sent alongside it.

Record a voice note on a PDF page

1. Open the PDF in Fileso and enter Annotate mode.
2. Tap Insert → Audio → Record Audio. Allow microphone access if iOS asks for it.
3. Record your note. You can pause and resume; tap Done when the clip is ready.
4. Tap the place on the PDF page where its sound icon should appear.
5. Tap Save, close the PDF, and reopen it. Select the sound icon and use Play to check the embedded note.

Place the icon near the paragraph or image it explains. A short note is easier for someone else to review than a long recording with no clear connection to the page. If you leave the recorder with a clip in progress, Fileso asks whether to keep recording or discard it.

Use an existing recording or a video’s sound

Choose Insert → Audio → Audio from Files for an audio file. To use a video in Photos, choose Audio from Video; Fileso extracts its audio track and places that sound in the PDF. It does not embed the video image. After either import finishes, tap the page to place the icon and save the document.

Fileso decodes the source and stores sound in a PDF-compatible audio annotation. This can increase the PDF’s size, especially for a long clip. Audio files over 100 MB, empty files, videos with no audio track, and files that cannot be decoded are rejected. For a long meeting recording, consider sharing the audio separately and adding a short spoken summary to the PDF.

Check the saved PDF before sharing

Reopen the document in Fileso and play the note. The selected icon also offers Share Audio if the recipient needs a separate audio file. The PDF specification defines Sound annotations, but viewers decide how to display and play them; test the PDF in the recipient’s reader when playback there matters. A viewer that does not expose the sound controls may still show the rest of the PDF.

If recording cannot start, check microphone access in iOS Settings. If saving fails, keep the PDF open and resolve the error before assuming the note is embedded. For a supporting document that should travel inside the PDF as a file, use the file attachment guide.