1. A method of determining an estimated neural response in a hybrid acoustic-electrical audio prosthesis comprising: recording a B response by target nerve tissue to a first stimulus sequence which includes: i. delivering to the target nerve tissue a first stimulus pulse P 1 to elicit a corresponding action potential followed by a relative refractory period, and ii. after the relative refractory period, delivering to the target nerve tissue a second stimulus pulse P 2 and an associated acoustic stimulation signal; recording an E response by the target nerve tissue to a second stimulus sequence which includes: i. delivering to the target nerve tissue a third stimulus pulse P 3 to elicit a corresponding action potential followed by a relative refractory period, and ii. within the relative refractory period, delivering to the target nerve tissue a fourth stimulus pulse P 4 ; recording a C response by the target nerve tissue to delivery of a first reference stimulus pulse P 5 corresponding to the first stimulus pulse P 1 ; recording a D response by the target nerve tissue to delivery of a second reference stimulus pulse P 6 corresponding to the third stimulus pulse P 3 ; processing the recorded responses to determine an artifact canceled estimated neural response Y following the relation Y=(B−C)−(E−D).