in decibels. A fade that works on a logarithmic scale would thus counteract the curve of a linear fade. In fade-ins the shape of the perceived volume curve looks like the level in decibels pulled towards the middle part of the line to the bottom right corner. The fade-out in turn looks like it has been pulled toward the bottom-left corner. A logarithmic fade takes a line that has already been curved and straightens it out [15]. The logarithmic fade sounds consistent and smooth since the perceived volume is increased over the whole duration of the fade. This makes this curve very handy for fading standard pieces of music. It is best used on a long fade-out since the fade has a perceived linear nature. Also a fade-out sounds very neutral when incorporated to parts of music with natural ambience. In crossfades this type of curve sounds very natural. When this curve is applied the perceived volume of the fade's midpoint is at about 50% of the maximum – when the two sections are summed the output volume is fairly constant. Exponential The exponential curve shape is in many ways the precise opposite of the logarithmic curves. The fade-in works as follows: it increases in volume slowly and then it shoots up very quickly at the end of the fade. The fade-out drops very quickly (from the maximum volume) and then declines slowly again over the duration of the fade. Simply stated a linear fade could thus be seen as an exaggerated version of an exponential fade in terms of the apparent volume. Thus the impression that would be gathered from an exponential curve's fade would sound as though the sound was rapidly accelerating towards the listener. Natural ambience can also be repressed by using an exponential fade-out. A crossfade, in the exponential shape, will have a perceivable dip in the middle, which is very undesirable in music and vocals. This depends largely on the length of the crossfade, a long crossfade on ambient sounds can sound perfectly satisfactory (the dip can add a little breath to the music). Exponential crossfades (or a curve with a similar shape) have a smaller drop in the middle of the fade. S-curve The S-curve shape is interesting since it has qualities that correlate with the previously mentioned curves. The level of the sound is 50% at the midpoint, but before and after the