The boundary element method is a powerful tool in computational acoustic analysis. The Boundary Element Method in Acoustics serves as an introduction to the method and goes on to complete the development of computational models. Software implementing the methods is available. Boundary element methods are developed for three important classes of acoustic or Helmholtz problems: modelling the acoustic field either interior or exterior to a closed surface or carrying out an acoustic modal analysis. Each class of problem is considered in two, three dimensions and the axisymmetric case. A very general development of the methods is followed so that the widest range of engineering problems are covered. Fortran 77 codes implementing the methods are available. Test problems are used to demonstrate the methods. Examples of realistic application such as vehicle noise and loudspeaker design analysis illustrate the potential of the boundary element method in acoustic simulation.