1. A method for encoding audio channels, the method comprising: generating one or more cue codes for two or more audio channels, wherein at least one cue code is an object-based cue code that directly represents a characteristic of an auditory scene corresponding to the audio channels, where the characteristic is independent of number and positions of audio sources used to create the auditory scene; and transmitting the one or more cue codes, wherein the at least one object-based cue code comprises one or more of: (1) a first measure of an absolute angle of an auditory event in the auditory scene relative to a reference direction, wherein the first measure of the absolute angle of the auditory event is estimated by: (i) generating a vector sum of relative power vectors for the audio channels; and (ii) determining the first measure of the absolute angle of the auditory event based on the angle of the vector sum relative to the reference direction; (2) a second measure of the absolute angle of the auditory event in the auditory scene relative to the reference direction, wherein the second measure of the absolute angle of the auditory event is estimated by: (i) identifying the two strongest channels in the audio channels; (ii) computing a level difference between the two strongest channels; (iii) applying an amplitude panning law to compute a relative angle between the two strongest channels; and (iv) converting the relative angle into the second measure of the absolute angle of the auditory event; (3) a first measure of a width of the auditory event in the auditory scene, wherein the first measure of the width of the auditory event is estimated by: (i) estimating the absolute angle of the auditory event; (ii) identifying two audio channels enclosing the absolute angle; (iii) estimating coherence between the two identified channels; and (iv) calculating the first measure of the width of the auditory event based on the estimated coherence; (4) a second measure of the width of the auditory event in the auditory scene, wherein the second measure of the width of the auditory event is estimated by: (i) identifying the two strongest channels in the audio channels; (ii) estimating coherence between the two strongest channels; and (iii) calculating the second measure of the width of the auditory event based on the estimated coherence; (5) a first degree of envelopment of the auditory scene, wherein the first degree of envelopment is estimated as a weighted average of coherence estimates obtained between different audio channel pairs, where the weighting is a function of the relative powers of the different audio channel pairs; (6) a second degree of envelopment of the auditory scene, wherein the second degree of envelopment is estimated as a ratio of (i) the sum of the powers of all but the two strongest audio channels and (ii) the sum of the powers of all of the audio channels; and (7) directionality of the auditory scene, wherein the directionality is a weighted sum of the width of the auditory event and the degree of envelopment of the auditory scene.