This paper presents theoretical approaches for the acoustic analysis of concentrated suspensions and emulsions. The aim is an extension of the well-established single-particle theory of Epstein, Carhart, Allegra, and Hawley (ECAH), by introducing effective ways of accounting for the effect of interacting neighboring particles. After discussion of three modeling approaches and their implementation into the general ECAH framework, and demonstration of their effect on the acoustic field, the behavior of each thus defined model is analyzed as a function of particle concentration. In all cases, convergence to the well-established ECAH result is observed in the dilute limit. At high concentrations, particularly good behavior is found for a core-shell (pseudofluid) model, both for suspensions and emulsions. This model correctly predicts an increase of attenuation with particle concentration which is less than linear, in agreement with experimental observations.