The voice is a physical phenomenon that conveys information. This information lies not only in the contents of the pronounced speech, but also in the characteristics of the vocal signal. Voice features allow one to identify the speaker, and provide information on her/his origin, gender, age, health condition, emotional condition, etc. Voice can be protected both by copyright law and by personal data law. Consequently, controllers and processors of voice data must make sure they comply with the provisions of personal data law (e.g., the GDPR), which requires careful design of their systems in order to implement key principles such as privacy by design.