There is provided a cerebrum evaluation device forevaluating the state of the cerebrum of a subject by analyzinga speech signal of the subject by using chaotic signal processingutilizing the periodicity of the signal. The cerebrumevaluation device evaluates the state of the cerebrum accordingto the speech signal uttered by the subject. The cerebrumevaluation device includes: a statistic information databasecontaining chaotic index values of speech signals of a pluralityof subjects a speech signal acquisition unit for acquiring aspeech signal a chaotic index value calculation unit forcalculating a chaotic index value of the speech signal by thechaotic signal processing utilizing the periodicity of the speechsignal acquired an evaluation unit for evaluating the state ofthe cerebrum of the subject according to the calculated chaoticindex value by referencing the statistic information databaseand an output unit for outputting the result evaluated by theevaluation unit.
