Recently, García et al. [Phys. Rev. E 67, 046606 (2003)] studied theoretically several acoustic devices with dimensions on the order of several wavelengths. Those authors also discussed experimental results previously reported by several of us [Cervera et al., Phys. Rev. Lett. 88, 023902 (2002)] and concluded that it is diffraction rather than refraction that is the dominating mechanism explaining the focusing effects observed in those experiments. In this Comment we reexamined their calculations and discussed why some of their interpretations of our results are misleading.

• Received 24 November 2003

DOI:https://doi.org/10.1103/PhysRevE.71.018601