Abstract: The invention relates to a hearing aid device in which the slices (s.sub.1, x.sub.2) of the electrical signal corresponding to each acoustic signal comprised respectively between 1500 and 3500 Hz and between 5000 and 7000 Hz, are transposed into compensation signals (S.sub.1, S.sub.2) comprised within two coupled ranges of separate low frequencies above the range 60 to 800 Hz, alone preserved without compensation. To preserve the timbres of the transposed sounds, the compensation signals are obtained by multiplying each slice (x.sub.1, x.sub.2) by itself or by a signal (x'.sub.1, x'.sub.2) deduced from this slice by amplitude equalization.