Yes, I recall not knowing how the sound was made - and so it was initially intriguing. It sounded better on Slam's earlier dates as recording of the time merged the two sound sources. I've heard it caught by modern recording where the far from perfect integration of voice and bass is exposed. Essentially I see its main value as entertaining, rather than musical - much like when Steve Turre lays down his trombone and takes up a seashell, to the delight of audiences.