All of the percussion on "An Eagle in Your Mind" was created using cut up samples of Mike's girlfriend's voice. 
A video (made for the WATMM video contest) was created for "An Eagle in Your Mind" by "Jesse Anderson" using stock footage sampled from Tatsuo Sato's anime film "Cat Soup." This video also offers an interpretation of the vocal sample heard during the track.
Between 1:53 and 2:50, a speech sample can be heard. It comes from the documentary "On the Tracks of the Wild Otter (1983)" , narrated by Hugh Miles. The sample can be heard at around 26:38 , and says :
The holts are nearly always close to the sea
in fallen boulders, old ruins, and cliffs
all at the top of a stack, like this
High above the sea
A safe place for cubs
I wait, tense
She leaves her spraint to notify others of her visit
The holts are evenly spaced
about 500 yards apart, [enough for the use of any otter who passes by?], with or without cubs
Right after this sample, around 2:50, a different voice, saying "I love you", is heard.
[JimE] noticed something else:
"there's a background sound throughout the song which could be "sweat-sweat" (in the first part of the song), with "tension" coming in later. It's hard to recognise as speech, but it could well be; one of the interviews says that the "percussion" in the track was constructed using the voice of the girlfriend of one of BoC."
A voice that sounds like a black male singing "No" fades in at 4:35 and continues throughout the song. (Sounds like another 70s/80s disco/funk sample). At 5:27 A scratchy sample saying "Yeah" is played forward, then backward, then forward again, with some additional scrubbing in between. At 6:00, "Yeah" plays again, but only once.