A method and a device for improving voice quality on transparent telecommunications-transmission paths. The audio-transmission channel is adapted to the respective audio-spectrum of the speaker at predetermined intervals. As a result, means for analyzing the voice signals in relation to the useful band width and amplitude thereof are provided in addition to means for influencing the band width and amplitude of the audio-transmission channel according to the determined useful band and amplitude. Such means can be installed in the communication terminal as well as in the communication network.