| 摘要 |
In digital hearing devices (1), it is common to use an ADC (5) which has a dynamic range only nearly large enough to comprise the dynamic range of typically encountered acoustic signals. A reduction of the preamplifier gain (G, G1, G2) thus needs to be applied when very loud signals are received in order to avoid clipping. It is known to temporarily reduce the preamplifier gain (G, G1) with fast attack and release times when a clipping of the input signal (M, AT, A) in the digitiser (5) is expected. The invention aims at improving the perceived signal quality of the audible signal provided to the user of the hearing device (1). This is achieved by simultaneously providing relatively fast and relatively slow temporary reductions of the amplifier gain (G, G1, G2) such that the slow gain reductions reduce the occurrences of fast gain reductions. This allows the hearing device (1) to provide a high quality sound to the user where clipping is reduced due to the fast gain reductions and where signal artefacts, such as pumping and switching noise, produced by the fast gain reductions is reduced due to the slow gain reductions. |
