1. A method for screening for diseases, the method comprising: performing a signal analysis of a speech sample received from a subject, the signal analysis comprising extracting cepstral coefficients from the speech sample and identifying articulation range and articulation rate using the cepstral coefficients extracted from the speech sample, and analyzing language patterns, wherein the analyzing of the language patterns comprises analyzing the language patterns to determine if an indicator of a neurological disease is present; determining a likelihood and type of a disease based upon the articulation range and articulation rate identified by the signal analysis of the speech sample, as well as the analyzing of the language patterns; and outputting information indicating the likelihood and type of the disease, wherein the cepstral coefficients from the speech sample are human factor cepstral coefficients or mel-frequency cepstral coefficients.