24. In a computer-implemented auditory training exercise for improving a person's acoustic processing abilities, wherein the auditory training exercise aurally presents a plurality of confusable pairs of synthesized phonemes, at a plurality of stimulus levels, to the person and challenges the person to make consonant and vowel discriminations under conditions of forward and backward masking from adjacent vowels and consonants, a method of progressively orienting the person to recognize a synthesized phoneme that consists essentially only of formants of the phoneme, the method comprising: generating a relatively simple, formant synthesized representation of a phoneme, the formant-synthesized representation consisting essentially only of formants of the phoneme; generating a relatively more naturalistic representation of the phoneme thru synthesis using a naturalistic time-varying filter; blending different proportions of the formant-synthesized and relatively more naturalistic auditory representations of the phoneme into different blended representations of the phoneme ranging from a most naturally-sounding representation of the phoneme to a least naturally-sounding representation of the phoneme; initially aurally presenting the most naturally-sounding representation of the phoneme to the person; and aurally presenting progressively less-naturally sounding representations of the phoneme to the person; wherein the auditory training exercise is implemented after the person completes the orientation.
24. In a computer-implemented auditory training exercise for improving a person's acoustic processing abilities, wherein the auditory training exercise aurally presents a plurality of confusable pairs of synthesized phonemes, at a plurality of stimulus levels, to the person and challenges the person to make consonant and vowel discriminations under conditions of forward and backward masking from adjacent vowels and consonants, a method of progressively orienting the person to recognize a synthesized phoneme that consists essentially only of formants of the phoneme, the method comprising: generating a relatively simple, formant synthesized representation of a phoneme, the formant-synthesized representation consisting essentially only of formants of the phoneme; generating a relatively more naturalistic representation of the phoneme thru synthesis using a naturalistic time-varying filter; blending different proportions of the formant-synthesized and relatively more naturalistic auditory representations of the phoneme into different blended representations of the phoneme ranging from a most naturally-sounding representation of the phoneme to a least naturally-sounding representation of the phoneme; initially aurally presenting the most naturally-sounding representation of the phoneme to the person; and aurally presenting progressively less-naturally sounding representations of the phoneme to the person; wherein the auditory training exercise is implemented after the person completes the orientation. 25. The method as recited in claim 24 , wherein the format synthesized and naturalistic representations of the phonemes are computer generated by: synthesizing a glottal source for the phoneme; filtering the synthesized glottal source with formant resonators to produce the formant-synthesized phoneme; and processing the synthesized glottal source with a time-varying filter to produce the naturalistic phoneme, wherein the time-varying filter substantially matches the spectro-temporal properties of a natural production of the phoneme, and wherein the naturalistic phoneme at least partially replicates the natural production of the phoneme.