Despite 2-factor authentication and other modern approaches, authentication by password is still the most commonly used method on the Internet. Unfortunately, as analyses show, many users still choose weak and easy-to-guess passwords. To alleviate the significant effects of this problem, systems often employ textual or graphical feedback to make the user aware of this problem, which often falls short on engaging the user and achieving the intended user reaction, i.e., choosing a stronger password. In this paper, we introduce auditory feedback as a complimentary method to remedy this problem, using the advantages of sound as an affective medium. We investigate the conceptual space of creating usable auditory feedback on password strength, including functional and non-functional requirements, influences and design constraints. We present web-based implementations of four sonification designs for evaluating different characteristics of the conceptual space and define a research roadmap for optimization, evaluation and applications.