A LOW BIT SPEED TRANSFORMATION ENCODER / DECODER (44.1 KHZ OR 48 KHZ SAMPLING PROPORTION) (192 KBITS PER SECOND) FOR APPLICATIONS IN HIGH QUALITY MUSICAL EQUIPMENT IN THE DOMAIN DURATION ( 128 SAMPLE BLOCKS) SO THAT THE DELAY OF THE PROPAGATION OF THE SIGNALS OF THE SYSTEM IS SUFFICIENTLY SHORT FOR THE REAL-TIME AUDITOR FEEDBACK OF A HUMAN OPERATOR. PAIRS OF CAREFULLY DESIGNED ANALYSIS / SYNTHESIS WINDOWS ARE USED TO REACH SUFFICIENT TRANSFORMATION FREQUENCY SELECTIVITY DESPITE USING SHORT BLOCKS OF SAMPLE. A SYNTHESIS WINDOW IN THE DECODER HAS CHARACTERISTICS SUCH AS THE PRODUCT OF ITS RESPONSE AND THE ANALYSIS WINDOW IN THE ENCODER PRODUCES A COMPOSITE RESPONSE THAT ADDS TO A UNIT OF TWO ADJACENT OVERLAPPING SAMPLE BLOCKS. ADJACENT DOMAIN-TIME SIGNAL SAMPLE BLOCKS ARE OVERLAPPED AND ADDED TO CANCEL THE EFFECTS OF THE SYNTHESIS AND ANALYSIS WINDOWS. A TECHNIQUE FOR DERIVING PAIRS OF SUITABLE ANALYSIS / SYNTHESIS WINDOWS IS PROVIDED. A DISCRETE TRANSFORMATION PROVIDED WITH A FUNCTION EQUIVALENT TO THE ALTERNATIVE APPLICATION OF A DISCRETE COSINE AND BREAST TRANSFORMATION MODIFIED IN ACCORDANCE WITH THE TECHNIQUE OF CANCELLATION OF ALIAS OF THE TIME DOMAIN, OR ALTERNATIVELY DISCRETE, IS USED IN THE ENCODER. DOMAIN-FREQUENCY TRANSFORMED COEFFICIENTS. TRANSFORM COEFFICIENTS ARE NON-UNIFORMALLY QUANTIFIED BY ASSIGNING THEM A FIXED NUMBER OF BITS AND A VARIABLE NUMBER OF DETERMINED BITS BASED ON ADAPTATION IN A PSYCHOACOUSTIC MASK. A TECHNIQUE FOR ASSIGNING THE FIXED BIT AND THE SITUATIONS OF THE ADAPTED BITS IS DESCRIBED. TRANSMISSION OF LATERAL INFORMATION IN RELATION TO BITS LOCATED ADAPTABLY IS NOT REQUIRED. ERROR CODES AND PROTECTED DATA MAY BE COMPLETELY DISPERSED THROUGH FRAME OUTLETS FORMATTED FROM THE ENCODER TO REDUCE SENSITIVITY TO NOISE EXPLOSIONS.