The application relates to a hearing system comprising a hearing device (HD), the hearing device comprising an input transducer (IT) and an output transducer (OT). In a first mode of operation the input transducer is operationally coupled to the output transducer via a forward path. A configurable output combination unit (Co) in the forward path is electrically connected to the output transducer and configurable to provide either the forward path signal, output probe signal, or a mixture of both. The hearing system further comprises a configurable probe signal generator (PSG), an adaptive feedback estimation unit (FBE) for generating an estimate of an unintended feedback path comprising an external feedback path (FBP) from output transducer to input transducer, using an adaptive feedback estimation algorithm and being operationally coupled to the forward path, and a control unit for controlling the configurable probe signal generator. Using a near perfect (or almost perfect) sequence or sweep as output probe signal has the advantage that the adaptation rate of the adaptive algorithm for estimating the feedback path and/or the precision of the feedback path estimate can be optimized.