No, it's not a vintage muppet show recording. The high-pitched voice in the above is said to be that of a dead person: 'Feda', a young Indian girl (allegedly) who was the main 'control' personality for the celebrated English medium Gladys Osborne Leonard (1882-1968) while she was in a trance. Feda was said to have died around the year 1800, while the recording here was made on the 17th of November, 1932.
Mrs Leonard was extensively investigated by members of the Society for Psychical Research over a long period, from the First World War till after World War II. In general they came to conclude that the medium exhibited some sort of supernormal ability to receive information. The SPR made this recording of Mrs. Leonard in trance, which was recently released on the album Okkulte Stimmen - Mediale Musik: Recordings Of Unseen Intelligences 1905-2007 (note: the initial image on the video is the album cover, and is not Mrs Leonard – her picture appears around 1:40 in). The track is labeled "Mrs Leonard and Her Spirit-control "Feda" With Reverend W. S. Irving and T. Besterman".
Also on the album is another sitter and 'spirit voice', this one a whole lot spookier sounding. Titled "Mrs Leonard With Reverend C. Drayton Thomas - 'Not To Be Played'", I've embedded it below.
A fair portion of both audio tracks are very difficult to make out - if anyone knows of transcripts out there I'd love to see them.