Before revision:  Despite complex component trade-offs, the low-pass roll-off in absolute magnitude of NLC,  indicative of diminishing total charge movement, poses a challenge for the role of prestin in cochlear amplification at very high frequencies.
After revision:  Despite complex component trade-offs, the low-pass roll-off in absolute magnitude of NLC, indicative of diminishing total charge movement, poses a challenge for a role of voltage-driven prestin in cochlear amplification at very high frequencies.