The thing about Herbaliser is that they use sound bites and samples
from all over the place to add to their music. They also have many
collaborators adding to their music.
For example as you will see from the link below, the Dream Warriors
feature in "The Road of Many Signs", Steve Buscemi's voice is used in
"Who's The Realest?". In fact that quote from Steve Buscemi was the
focus of a question that appeared on here a while ago.
On "The Sensual Woman", they actually used a "New Age" Sex instruction
tape recording and mixed it in with their song. It is actually the
narrator of the instruction tape that they have mixed in.
Although they have sampled the tape, it is not credited on the Album
on any site, so I can only assume that it was a very obscure tape that
one of the band thought it might be funny to mix in.
Someone, who wasn't impressed by the use of this voiceover as it were,
is this reviewer at epinions.
I hope this helps