This "stereo emphasis" system is based on the well-known "physiologic effect". Location of a certain sound is given to the auditor by the high-frequencies component of the signal. This is why it often is really tough for most listeners to precisely locate where a double-bass is situated. Same for large drums, tubas, and everything emitting a sound lower than 100 Hz in the spectrum. This is also why, in many sound systems, only a single low-range enclosure is necessary. Especially home-systems. So, in these sound processors, sound engineers use this human ear sensitivity to higher pitched noises. By tweaking in the duration of the sound, its base frequencies and resonance frequencies, its volume relative to others, etc. they make us feel the sensation of facing a wider field of sound. Even with headphones/earphones, even though the smaller the transducer the tougher it is to create those "spatial" effects. Mainly because smaller membranes have a huge amount of work dealing with lower frequencies, they hardly can reproduce higher ones... they just can't handle both, plus those high-energy mid-tones that take lots of membrane travel to render properly. In low-end equipments, those systems are basic. But they get ultra-complicated in the better ones, such as what Sony recently released in their "home cinema" range : four enclosures create a sensation of be surrounded by 12 ones in the three dimensions, ceiling included. With this kind of small recorders, don't even bother using that function. Processors built-in can hardly do a good job. It shall be OK for recording conferences, because nobody knows how or have time to process the sound. But your skills and softwares enable you to do a way better job in your studio than this tiny thing ever will. Hope you have a better "picture" of how those sound processors operate...