Under the sponsorship of the Office of Naval Research (ONR), an integrated acoustic and oceanographic field experiment was conducted jointly by the Naval Postgraduate School (NPS), the Woods Hole Oceanographic Institution (WHOI), and the University of Rhode is land in the Middle Atlantic Bight (MAB) to study the propagation of sound from the continental slope onto the continental shelf. The primary goal of this thesis is to examine the influence of environmental factors on broadband transmission loss (TL) spectra near the shelf break by analyzing the power spectral density of Signal Underwater Sound (SUS) transmissions. Measured broadband spectra are compared to numerical solutions in an attempt to determine which environmental factors dominate the TL structure.