Abstract: A hearing aid with digital, electronic compensation for acoustic feedback comprises a microphone (5), a preamplifier (7), a digital compensation circuit (3), an output amplifier (9) and a transducer (11). The digital circuit (3) comprises a noise generator (33) for the insertion of noise, and an adjustable, digital filter (27) for the adaptation of the feedback signal. The adaptation takes place using a correlation circuit (31). The circuit further comprises a digital circuit (210) which monitors the loop gain and regulates the hearing aid amplification via a digital summing circuit (211), so that the loop gain is less than a constant K. The circuit further comprises a digital circuit (79) which carries out a statistical evaluation of the filter coefficients in the correlation circuit, and changes the feedback function in accordance with this evaluation.
Abstract: A protection element for the sound conduction channel (6) on an all-in-the-ear hearing aid (1) with a hearing aid housing (2) arranged to suit the user's auditory canal comprises an exchangeable filter elenment (3) which is snapped firmly on a sound conduction tube (5) which is disposed and secured in the hearing aid's sound conduction channel (6). The filter element (3) has a number of sound conduction openings (12). The invention also relates to a tool and a dispenser for use in the exchanging of the filter element (3).