This study aims to consider the significance of deciphering the Hebrew alphabet for the history of phonetic thought. Hermetic and Kabbalistic teachings endowed the Hebrew language with a divine meaning. Traditionally considered as given to Adam by God, this alphabet was called the Alphabet of Adam. The novelty and relevance of the current work are defined by the lack of a comprehensive description of the relationship between these traditional ideas and phonetics. The need for it is caused by the earlier observations about the possible influence of the 17th century concepts on the results of later measurements of vowels with tuning forks, and by the widespread opinion about the low significance of this period in linguistic science history. Though there can be found some publications devoted to concrete authors of the 16th-17th centuries, their contribution to the development of phonetic sciences has not yet been acknowledged. The current research is based on primary and secondary sources in Latin, English, French and Russian. The analysis showed that deciphering the vowels of Hebrew alphabet led to the first attempt to accurately describe vowel acoustic features, the empirical study of their articulatory characteristics and to the search for the “ideal” alphabet built of iconic signs. It also allowed the authors to develop methods for teaching deaf-mutes and systematize vowels. Thus the initial hypothesis about the significance of deciphering the Alphabet of Adam for the history of phonetic thought was confirmed. Refs 25.