A method of encoding a composite audio signal configured to passively support the development and maintenance of language processing capabilities in a listener, comprising the steps of: (a) constructing the composite audio signal comprising: (i) a background sound carrier envelope ; and (ii) an auditory sequence consisting of a series of a plurality of standard auditory signals and a plurality of novel deviant auditory signals ; wherein each of the plurality of standard auditory signals varies between about 2 to 300 ms in duration and about 40-10,000 Hz in frequency, and all auditory signals are 75 dB or lower, and wherein a pseudorandom number of at least one of the plurality of novel deviant auditory signals is presented at pseudorandom intervals within about 300 ms to about 3 sec of at least one of the plurality of standard auditory signals to construct the auditory sequence and the auditory sequence is then layered into the background sound carrier envelope to form the composite audio signal , wherein each novel deviant auditory signal differs from the standard auditory signal that immediately precedes it by at least one of amplitude, frequency, pitch, pattern and/or duration; and (b) playing back the composite audio signal on an audio playback device , wherein the played-back composite audio signal provides a sound enhancement environment that passively benefits the language processing capabilities in the listener. (a) constructing the composite audio signal comprising: (i) a background sound carrier envelope ; and (ii) an auditory sequence consisting of a series of a plurality of standard auditory signals and a plurality of novel deviant auditory signals ; wherein each of the plurality of standard auditory signals varies between about 2 to 300 ms in duration and about 40-10,000 Hz in frequency, and all auditory signals are 75 dB or lower, and wherein a pseudorandom number of at least one of the plurality of novel deviant auditory signals is presented at pseudorandom intervals within about 300 ms to about 3 sec of at least one of the plurality of standard auditory signals to construct the auditory sequence and the auditory sequence is then layered into the background sound carrier envelope to form the composite audio signal , wherein each novel deviant auditory signal differs from the standard auditory signal that immediately precedes it by at least one of amplitude, frequency, pitch, pattern and/or duration; and (i) a background sound carrier envelope ; and (ii) an auditory sequence consisting of a series of a plurality of standard auditory signals and a plurality of novel deviant auditory signals ; wherein each of the plurality of standard auditory signals varies between about 2 to 300 ms in duration and about 40-10,000 Hz in frequency, and all auditory signals are 75 dB or lower, and wherein a pseudorandom number of at least one of the plurality of novel deviant auditory signals is presented at pseudorandom intervals within about 300 ms to about 3 sec of at least one of the plurality of standard auditory signals to construct the auditory sequence and the auditory sequence is then layered into the background sound carrier envelope to form the composite audio signal , wherein each novel deviant auditory signal differs from the standard auditory signal that immediately precedes it by at least one of amplitude, frequency, pitch, pattern and/or duration; and (b) playing back the composite audio signal on an audio playback device , wherein <EOS>