The Narragansett Marine Laboratory, sponsored by the Office of Naval Research, undertook a systematic seasonal study of shallow water ambient sound, commencing in October, 1958. With a general lack of information on average values and the variabilities associated with these average values, it was decided to base the experimental work on a theoretical model, which would elicit systematic seasonal differences, if they existed, as well as suggest procedures for further sampling of shallow water ambient sound. The model selected was a mixed‐model, one‐way analysis of variance experimental design, constructed to determine the existence of significant seasonal differences among months of the year, specific hours in a day, as well as to determine the contribution made to any ambient noise spectrum by variability due to weeks of the month, days of the week, and minutes within any sampling hour.