Numerical simulation of the acoustic field for a large concert hall is normally executed by geometrical acoustics. Although it is a classical method, it needs considerable calculations for practical applications for a large hall. Therefore, some algorithmic technique is needed. As the simulated result contains three-dimensional information, its visualization is useful for intuitive understanding of the field. An auralization of the simulated result is also presented. Because the wave nature of the field should be considered for long wavelength sound, a wave acoustical simulation technique is proposed, which is based on a boundary-element method. A comparison of results from geometrical acoustics and wave acoustics is also presented.