Abstract: We study the problem of scattering of the quantized Dirac field by a noncommutative (Moyal-multiplication deformed) external potential, and present some technical results for this situation like unitary implementability of the scattering transformation in the case of commutative time, and existence of operators inducing the corresponding field-strength derivation in the general case. Moreover, we indicate how the ensuing operators can be interpreted as observables of the quantized field theory on a noncommutative Lorentzian spacetime in the spirit of Bogoliubov's formula. We explain how we wish to see this as a general method to assign quantum field observables to elements of a noncommutative algebra which is part of a "Lorentzian spectral triple", suggested as model-independent noncommutative generalization of Lorentzian spacetime.