Inclusion Criteria:  between 18 and 85 years of age non-smokers with a score of 0-2 out of 10 maximum on the Fagerström index of smoking dependency cognitive performance within two standard deviations of the CERAD mean  Exclusion Criteria:  less than 18 or greater than 85 years of age deafness or excessive hearing loss smokers with a score between 3 and 10 on the Fagerström index of smoking dependency history of psychiatric illness, neurological disorders, diabetes mellitus, renal failure, or cardiovascular disease regular use of prescription medications (excluding oral contraceptives) drug dependency