This Technical Report provides an overview of the requirements and tests of IEC 60601-2-66 in combination with the applicable sections of IEC 60601-1@ and the collateral standards of the IEC 60601 series. NOTE The IEC 60601 series consists of three levels of standards: IEC 60601-1@ known as the general standard@ several IEC 60601-1-X documents@ known as the collateral standards and a series of particular standards covering requirements for specific types of equipment (IEC 60601-2-X). It is intended to assist various groups involved in the product lifecycles process ?C like designers and suppliers ?C to get an overview of the basic requirements without studying all involved standard documents in detail. The table includes not all but just the more common requirements and tests. It is crucial to understand that the summary in this document cannot serve as an input for a product requirement specification or as a test plan without consulting the standard document itself. This Technical Report alone cannot be used to establish or assess compliance to the standard. The summary in Table 1 below does not preclude the user from reading the referenced standards in their entirety for a thorough knowledge of the basic safety of hearing instruments and hearing instrument systems.