A hearing aid includes a microphone for converting sound into an audio input signal, a hearing loss processor configured for processing the audio input signal or a signal derived from the audio input signal in accordance with a hearing loss of a user of the hearing aid, a synthesizer configured for generation of a synthesized signal based at least on a sound model and the audio input signal, the synthesizer comprising a noise generator configured for excitation of the sound model for generation of the synthesized signal including synthesized vowels, and a receiver for generating an output sound signal based at least on the synthesized signal.