An audio decoder (200; 800) for the provision of decoded audio information (212; 812) on the basis of an encoded audio information (210; 810), wherein the audio decoder comprises: an arithmetic decoder ( 230; 820) for the provision of a plurality of decoded spectral values (232; 822) on the basis of an arithmetically encoded representation (222; 821) of the spectral values comprised in the encoded audio information; and a converter from the frequency domain to the time domain (260; 830) for the provision of an audio representation in the time domain (262; 812) using the spectral values (232; 822), to obtain the information of decoded audio (212; 812); wherein the arithmetic decoder (230; 820) is configured to select a mapping rule (297; cum_freq []) that describes a mapping of a code value of the arithmetically encoded representation (222; 821) of the values spectral on a symbol code representing one or more of the decoded spectral values or at least a portion of one or more of the decoded spectral values depending on a context state described by a current context numerical value (c) ; and wherein the arithmetic decoder (230; 820) is configured to determine the current context numerical value (c) depending on a prior context numerical value and depending on a plurality of previously decoded spectral values, where the arithmetic decoder is configured to modify a numerical representation of the previous context numerical value, which describes a context state for decoding one or more previously decoded spectral values, depending on a context subregion value describing a context subregion, to obtain a representation numeric of a current context numerical value describing a state of the context for decoding one or more spectral values to be decoded.