This is an audio sample from a copyrighted musical recording, and falls under fair use due to:
The sample is being used for commentary on the music recording in question, and contributes significantly to the encyclopedia articles.
The sample is short in relation to the duration of the recorded track and is of an inferior quality to the original recording.
This sample does not diminish the copyright holder's ability to market the media.
The copyright for it is most likely held by either the publisher/producer and/or artist(s) producing the work in question. It is believed that the use of low-resolution images of character artwork qualifies as fair use under United States copyright law. Any other uses of this image, on Kingdom Hearts Wiki or elsewhere, may be copyright infringement. See Non-free content for more information.