In a retrospective analysis of data collected during the 1963 followup of the NAMRL Thousand Aviator Study, two hearing level groups were identified, normal and impaired, and compared along 33 non-auditory dimensions. It was discovered that these two equally noise-exposed groups could be differentiated according to their smoking history and eye color. That is, the impaired hearing group reported smoking more cigarettes for a greater period of time than did the members of the normal hearing group. Furthermore, blue-eye individuals were over-represented in the impaired hearing group and under-represented in the normal hearing group, whereas the reverse was true for brown-eyed aviators. This latter finding is consistent with reports linking temporary hearing loss and eye color. There was 31 other physical, psychological, and sociological measures which failed to appear differentially in the two groups.