Techniques for sensing neural responses such as Evoked Compound Action Potentials (ECAPs) in an implantable stimulator device are disclosed. A first therapeutic pulse phase is followed by a second pulse phase, which phases may be of opposite polarities to assist with active charge recovery. The second pulse phase is formed so as to overlap in time with the arrival of the ECAP at a sensing electrode, which second phase may generally be longer and of a lower amplitude. In so doing, a stimulation artifact formed in a patient's tissue is rendered constant, and of a smaller amplitude, when the ECAP is sensed at the sensing electrode, which eases sensing by a sense amp circuit. Passive charge recovery may follow the second phase, which will not interfere with ECAP sensing that has already occurred.