 Numerous other composers, artists and writers followed suit, making synesthesia well known among the artistic community of the day.Due to the difficulties in assessing and measuring subjective internal experiences, and the rise of behaviorism in psychology, which banished any mention of internal experiences, the study of synesthesia gradually waned during the 1930s.Marks lists 44 papers discussing colored hearing from 1900 to 1940, while in the following 35 years from 1940 to 1975, only 12 papers were published on this topic.