Subtitles are a way for providing translation from one language to another for content on your website.
Captions are the method for providing a text alternative for visitors who have hearing issues or simply are not using technology that plays sound.
Captions provide dialogue, who is speaking, and non-speech information conveyed through sound, including meaningful sound effects.
When providing caption to an audio file, it is important to specify that the attribute kind="captions". The following is a sample of captions being provided to an audio element.
<audio>
<source src="myAudioFile.mp3" type="audio/mp3">
<track src="myAudioCaptions.vtt" kind="captions" srclang="en" label="english_captions">
</audio>
Note: Be sure that a .vtt corresponding file exists for the audio file and that you are providing the correct path to that file on the website. If you do not have a captions file for your audio, it is advisable to provide a transcript. A transcript can always be utilized to later create a captions file.