The National Acoustic Laboratories (NAL) has introduced a new procedure for fitting non-linear hearing aids (NAL-NL1). The aim of NAL-NL1 is to maximise speech intelligibility for a range of input levels while normalising the overall loudness of speech. This rationale results in the loudness of speech bands being equalised across frequencies, which is a very different result from several other fitting procedures for non-linear hearing aids that mainly aim at normalising loudness of speech bands. This talk presents data from an evaluation study where NAL-NL1 is compared to a loudness normalisation procedure (the IHAFF protocol based on the Contour test and the Visual Input/Output Locator Algorithm). Twenty-four subjects with flat and steeply sloping losses have completed a paired comparison test and a speech recognition test in the laboratory, and a field test. Overall, NAL-NL1 is the preferred response for listening to speech in quiet and in background noise, and significantly better performances are obtained with NAL-NL1 in background noise.