{'fraction_non_alphanumeric': 0.022641509433962263, 'fraction_numerical': 0.022641509433962263, 'mean_word_length': 6.273972602739726, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
History of environmental acoustics, 1960's to 2000's

Building on oceanographic and wave physics knowledge bases assembled over the prior century, environmental acoustics research has made steady progress since the 1960's. Developments in waveguide propagation theory, acoustic theory of heterogeneous media, data acquisition electronics, data storage capability, navigational precision and computational power have each enabled this progress. An overview of these developments and the resultant scientific progress is given here.