Is there a way to convert .mp3 audio to .mka format?
Converting MP3 Audio Files directly to Matroska Audio Files (.mp3 to .mka conversion) is possible and should be quite straightforward.
Use an audio editing software or (online) conversion tool, such as Freemake Audio Converter, which allows users to import MP3 audio files and export them in MKA format.
A popular free audio converter
One of the most popular and successful free video conversion softwares