Propagation of acoustic waves in the atmosphere is affected by several mechanisms. Two of the effects are the scattering of sound by small-scale atmospheric turbulence and fluctuation of the speed of sound gradients by the passage of large-scale atmospheric turbulence. Small- and large-scale atmospheric turbulence causes the acoustic waves to be altered by different mechanisms. Until recently, the majority of work in turbulence effect on acoustics has concentrated on the small-scale turbulence regime of the inertial subrange of the Kolmogorov spectrum. Earlier small-scale turbulence models have concentrated on the statistical-based work of Tatarski. Current turbulence models deal more with the structural nature of the turbulence because the statistical approach does not account for all of the turbulence effects being measured during acoustic propagation experiments. The large-scale turbulence problem cannot be handled very well with a statistical approach to atmospheric turbulence because the regime of the large-scale turbulence extends into the energy containing subrange or sometimes referred to as the source region. This report discusses the current and past turbulence models used to treat the effect of small- and large-scale turbulence on atmospheric acoustic propagation. (AN).