Method for encoding an analog speech signal scanned at a scanning rate, which is divided into time frames and which is compared to a synthetic signal (As_syn), a. wherein the synthetic signal (AS_syn) is formed time frame by time frame by means of a synthesis filter (A (z)), which is excited by an excitation signal (exc), and b. the excitation signal (ecx_p, exc) is formed with the use of at least one adaptive code list, in which an earlier excitation signal (old_exc) is present as a plurality of scanning values, provided with a defined scanning space, wherein the adaptive code list comprises an N-times higher band width than the scanning rate, as a result of which an N-th lower space is formed by the formation of intermediate values between the scanning values, where N is an integer number greater than or equal to 2, and c. for the current excitation signal (exc_p, exc) a segment corresponding to the length of the time frame is selected from the plurality of scanning values by means of a speech-based frequency parameter (p), which also assumes values which are not whole numbers, and d. in the event of the speech-based frequency parameter (p) not assuming a whole-number value, intermediate values which are to be interpolated and are defined by the speech-based frequency parameter (p) are formed to the scanning values, such that a reduction of the temporal interval between the intermediate values and the scanning values occurs, e. and this totality of intermediate values and scanning values is used for the formation of the excitation signal (exc_p, exc), as a result of which an effective higher band width is attained, as a result of which the quality of a synthetic signal reproduced on a receiver side is improved. a. wherein the synthetic signal (AS_syn) is formed time frame by time frame by means of a synthesis filter (A (z)), which is excited by an excitation signal (exc), and b. the excitation signal (ecx_p, exc) is formed with the use of at least one adaptive code list, in which an earlier excitation signal (old_exc) is present as a plurality of scanning values, provided with a defined scanning space, wherein the adaptive code list comprises an N-times higher band width than the scanning rate, as a result of which an N-th lower space is formed by the formation of intermediate values between the scanning values, where N is an integer number greater than or equal to 2, and c. for the current excitation signal (exc_p, exc) a segment corresponding to the length of the time frame is selected from the plurality of scanning values by means of a speech-based frequency parameter (p), which also assumes values which are not whole numbers, and d. in the event of the speech-based frequency parameter (p) not assuming a whole-number value, intermediate values which are to be interpolated and are defined by the speech-based frequency parameter (p) are formed to the scanning values, such that a reduction of the temporal interval between the intermediate values and the scanning values occurs, e. and this totality of intermediate values and scanning values is used for the formation of the excitation signal (exc_p, exc), as a result of which an effective higher band width is attained, as a result of which the quality of a synthetic signal reproduced on a receiver side is improved.