Inclusion Criteria  Aged 18 years of age or older. Referred to the echocardiogram laboratory for routine clinically indicated echocardiography, or to the cardiac catheterization laboratory for routine clinically indicated catheterization procedures Individuals with normal heart sounds, isolated aortic stenosis (any degree of severity), or isolated mitral regurgitation (any degree of severity)  Exclusion Criteria  Patients with unstable cardiovascular or pulmonary disease Patients with mixed valvular heart disease, corresponding to more than one type of valve pathology (i.e.: Aortic stenosis and Aortic Regurgitation), or more than 1 valve involved (i.e.: aortic stenosis and mitral regurgitation)