Vocal dosimeters may be used to characterize long-term voice production in typical daily activities. The reliability of four vocal dosimeter devices in the estimation of Sound Pressure Level (SPL) and fundamental frequency (Fo) was assessed. The devices evaluated were the Ambulatory Phonation Monitor (KayPENTAX), VoxLog (Sonvox), VocaLog (Griffin Laboratories), and Voice-Care (PR.O.VOICE). Twenty subjects were recorded in a sound booth by means of a head-mounted microphone while using each dosimeter. Subjects were asked to produce a sustained /a/ vowel and to read a text in three different voice styles (relaxed, normal, and raised). On the basis of the difference in the estimation of the parameters between the values acquired from the HMM and the dosimeters, the mean error, and the combined uncertainty were calculated. For the SPL, the dosimeter with the highest mean error was the APM, followed by the VoxLog, the VocaLog, and the Voice-Care. For Fo, the dosimeter with the highest mean error was the VoxLog, followed by the Voice-Care, and the APM (the VocaLog does not monitor Fo).