Privacy-enhancing technologies (PETs) provide technical building blocks for achieving privacyby design and can be defined as technologies that embody fundamental data protection goals[13 ] including the goals of unlinkability, interveneability, transparency and the classical CIA(confidentiality, integrity, availability) security goals by minimizing personal data collectionand use, maximizing data security, and empowering individuals.The privacy by design principle of a positive sum for speech and language technologiesshould enable users to benefit from the rich functions of these technologies while protectingthe users’ privacy at the same time. The fundamental question is how to achieve privacyby design for speech and language technology without hampering the services. To achievethis goal, different PETs exist that can be utilized for this purpose. Below, we first discusswhat type of personal data are accessible via speech and text and should be the target ofprotection by PETs. Then, we provide an overview of PETs that can provide protectionand discuss their limitations and challenges that arise when used for speech and languagetechnologies.