1. A method for processing a signal, the method comprising: obtaining, by an audio coding apparatus, a codeword corresponding to an entropy-encoded entropy table index, wherein variable bits are allocated to the codeword based on frequency of use; obtaining an entropy-decoded entropy table index by entropy-decoding the codeword; identifying, from among multiple entropy tables used for decoding data, a particular entropy table using the entropy-decoded entropy table index; and entropy-decoding the data using the particular entropy table, wherein the entropy-decoded entropy table index indicates at least one value which corresponds to a largest absolute value (LAV) among multiple indexes included in the particular entropy table.