Variations of the low-frequency sound field are considered when a train of nonlinear internal waves (NIW) crosses the acoustic track during one hour. This experimental situation took place in the Shallow Water 2006 experiment (SW06), conducted on the New Jersey continental shelf region during June-August 2006. In this paper, four intervals of sound transmissions (each about ∼ 7.5 minutes) is considered. Wave fronts of the NIW train were almost parallel to direction of the 25 km acoustic track. An L-shaped receiving array with horizontal part of about 450 m and vertical part of about 55 m (VHLA) was used to observe vertical and horizontal interference patterns for different geotimes. Fluctuations of interference pattern on VHLA were studied to estimate spatial and temporal scales of acoustic intensity fluctuations. It is shown that the sound field fluctuations observed on the VHLA are due to horizontal refraction provided by the motion of the NIW train. Estimated average values of horizontal angle measured during the experiment are in a good agreement with the theoretical values.