A method for fitting a hearing instrument comprises obtaining sensor data from a plurality of sensors belonging to a plurality of sensor types; applying a machine learned (ML) model to determine, based on the sensor data, an applicable fitting category of the hearing instrument from among a plurality of predefined fitting categories, wherein the plurality of predefined fitting categories includes a fitting category corresponding to a correct way of wearing the hearing instrument and a fitting category corresponding to an incorrect way of wearing the hearing instrument; and generating an indication based on the applicable fitting category of the hearing instrument.