Although the fundamental resonance frequency of a Helmholts resonator is mainly determined by the volume of the resonator and the size of the hole, it is also affected by the position of the hole and the shape of the resonator. In this study, the inertial end corrections and the fundamental resonance frequencies of concentric pipe resonators are estimated for various positions of the hole and shapes of the resonator by using the 3-D analysis. For an effective noise reduction in concentric pipe resonators with several holes, an optimal spatial hole-distribution is proposed based on the calculated transmission loss for various hole-distributions and sizes of holes.