In this demonstration, which was originally described by Smoorenburg (1970), a two-tone complex of 800 and 1000 Hz is followed by one of 750 and 1000 Hz. If you listen analytically, you will hear one partial go down in pitch; if you listen synthetically you will hear the pitch of the missing fundamental go up in pitch (a major third, from 200 to 250 Hz).
H.L.F. von Helmholtz (1877), On the Sensation of Tone, 4th ed. Transl., A.J.Ellis, (Dover, New York, 1954).
G.F.Smoorenburg (1970), "Pitch perception of two-frequency stimuli," J. Acoust. Soc. Am. 98, 924-942.
E.Terhardt (1974), "Pitch, consonance and harmony," J. Acoust. Soc. Am. 55, 1061-1069.