This paper focuses on the definition of calibration procedures that ensure the traceability of parameters estimated by vocal analyzers based on a contact microphone. The common estimated parameters are sound pressure level, fundamental frequency and time dose, which have been proposed for diagnostic purposes. An analysis is also proposed in order to estimate the uncertainty of the investigated parameters, taking the contributions related to the defined calibration procedures into account. Specific tests will be also defined in order to identify the main influence quantities and their effects on the estimated parameters. Preliminary results are reported that refer to a device developed by the authors, which uses an electret condenser microphone as the contact microphone.