At first glance, mp3 to docx conversion does not make much sense because first one is audio file and the second one a document, yet it is not complete nonsense.
For example when working on a document in Microsoft Word you have the option to import OLE objects, which may also be MP3 audio files. You can create a Microsoft Word document with an MP3 embedded so it can be played on some page of the document. This can be done either in Microsoft Word itself with the audio embedding function, or through some dedicated converter.
Another example would be various mp3 tag editors and similar software tools with which you can export embedded information from mp3 files (photos, album covers, lyrics or other additional information) and then paste it into Microsoft Word.
And of course there is also the possibility of audio to text conversion which is typically used for conversion of recorded speech to text, something that can be done with programs and services like VoiceBase.
It is however unlikely that you will find something like mp3 to word document converter on the Internet.Open MP3 file Open DOCX file
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