The "transpose" knob in Ableton Live 9 only allows transposing down 48 semitones, which is 4 octaves.
In order to best approximate what a bat hears, I'd like to transpose down 6 octaves, which is 72 semitones. I could record one track into another, and then transpose that one down again. But I'd prefer to find a way to do it, you know, live. That way I can see how different songs sound with it.