I am sorry if I come up as a rude imbecile but one question - Have you had a stutter ? Or maybe if you would like to quote some research papers that sight that a resurfacing of Stuttering is a sign of cognitive decline ? I am not that 'gotcha' type of person , I am just genuinely curious if there is something about stuttering I missed . I really hope that you are able to differentiate between 'stutter by birth or by childhood' and 'other forms of speech impediment due to Aging' . Thank You for reading my comment .