Long‐term (one‐year) open ocean measurements of ambient acoustic noise were made in the N.E. Pacific Ocean using instrument packages placed on seamounts. The seamounts Cobb [summit 15 fathoms (f)], Union (summit 160 f), and Bowie (summit 16 f), extended over612°of latitude in a near N‐S direction. Packages were placed on seamounts Cobb and Bowie on terraces at about the 110‐f level and on Union near the summit at about the 170‐f level. Averaged 4‐min samples of noise level in the 150‐ to 300‐Hz frequency baud were obtained once per hour and recorded as a bar graph on strip paper chart. Usable data yield was about 50%. The data are presented in the form of histograms of frequency of occurrence of noise level in 5‐dB intervals by months. There appears to be about a 4‐dB increase in noise level in the band in the winter months. A brief description of the instrument package and the technique used for placement and recovery will be given.