A hearing aid is fitted to an individual and/or the individual is trained in hearing with the hearing aid. In a first step a stimulus signal is provided. In a second step, the stimulus is presented to the individual. In a third step, a response of the individual in regard to the stimulus is obtained. In a fourth step a hearing aid parameter is adjusted based on the response. In an alternative or additional fourth step, a further stimulus signal is selected based on the response. The second step of presenting the stimulus signal comprises the sub-steps of obtaining a first and second signal based on the stimulus signal. In a further sub-step, the first signal is processed and presented by the hearing aid. Simultaneously, in a further sub-step, the second signal is presented by a supplementary loudspeaker for improving the stimulus presentation in regard to direct sound.