Psychology / Cognitive Science / Speech Acoustics / Brain and Cognition / Humans / Fundamental Frequency / Case Study / Pilot study / Longitudinal Studies / Adult / Retrospective Studies / Cross sectional Study / Early Diagnosis / Neurosciences / Predictive value of tests / Parkinson Disease / Fundamental Frequency / Case Study / Pilot study / Longitudinal Studies / Adult / Retrospective Studies / Cross sectional Study / Early Diagnosis / Neurosciences / Predictive value of tests / Parkinson Disease