The effect of hearing-aid compression on judgments of relative distance.

The overall level of a sound is an important auditory cue to distance in rooms, but this cue might be affected adversely by the amplitude compression found in most modern hearing aids because this explicitly changes levels. This prediction was tested using a synthetic-distance design to measure the just-noticeable difference (JND) in distance from distances of 2 or 5 m. Twenty-six aided listeners participated. The results did not show any effect of compression ratio upon JNDs. A possible interpretation is that the listeners had acclimatized to the effect their aids have on level.