Micro-augmentations provide novel ways to interact directly with the past. This is a new concept that uses minimum stimulation to achieve maximum effects in spaces of cultural heritage. We experiment with new implicitly interactive and almost transparent museum technologies to create a holistic emotional visitor experience and solve a number of museum problems (i.e. misconceptions, intra-group communications, and visitor engagement). The paper presents the rationale for the design decisions, as well as the technical challenges faced during implementation. Audio micro-augmentations were firstly used at the UCL Grant Museum of Zoology. Initial user testing data from the system's calibration phase at that museum revealed the entertaining and learning potential of the application, together with issues for future development.