A state control apparatus (100; 200) comprising: a detecting unit (102; 302) including a detecting device comprising an enzyme sensor disposed at a position close to outlets of a gland and configured to detect an enzyme secreted from the gland, the enzyme being a saliva amylase and the state control apparatus being an intraoral device; an acquiring unit configured to acquire an enzyme activity level of the detected enzyme by calculating the enzyme activity level based on the detected enzyme, wherein the enzyme is an enzyme whose time constant of reaction to an external stimulus is within a predetermined period or an enzyme whose time constant is shorter than the predetermined period, and wherein the acquiring unit is further configured to calculate the enzyme activity level based on the detected enzyme according to a detection result of the detecting device; and a state control unit comprising a bone-conduction module and configured to: determine, among a content list of content data, a content data based on the acquired enzyme activity level and a time-series pattern of the enzyme activity level which is associated with the content data and which indicates a pattern of temporal change of the enzyme activity level, the content list of content data having respective patterns of temporal change of the enzyme activity level during reproduction of the content data, wherein the content data is determined in that it has pattern of temporal change opposite to the acquired pattern of temporal change of the acquired enzyme activity level, and reproduce the content data by utilizing a bone-conduction function of the bone-conduction module. a detecting unit (102; 302) including a detecting device comprising an enzyme sensor disposed at a position close to outlets of a gland and configured to detect an enzyme secreted from the gland, the enzyme being a saliva amylase and the state control apparatus being an intraoral device; an acquiring unit configured to acquire an enzyme activity level of the detected enzyme by calculating the enzyme activity level based on the detected enzyme, wherein the enzyme is an enzyme whose time constant of reaction to an external stimulus is within a predetermined period or an enzyme whose time constant is shorter than the predetermined period, and wherein the acquiring unit is further configured to calculate the enzyme activity level based on the detected enzyme according to a detection result of the detecting device; and a state control unit comprising a bone-conduction module and configured to: determine, among a content list of content data, a content data based on the acquired enzyme activity level and a time-series pattern of the enzyme activity level which is associated with the content data and which indicates a pattern of temporal change of the enzyme activity level, the content list of content data having respective patterns of temporal change of the enzyme activity level during reproduction of the content data, wherein the content data is determined in that it has pattern of temporal change opposite to the acquired pattern of temporal change of the acquired enzyme activity level, and reproduce the content data by utilizing a bone-conduction function of the bone-conduction module. determine, among a content list of content data, a content data based on the acquired enzyme activity level and a time-series pattern of the enzyme activity level which is associated with the content data and which indicates a pattern of temporal change of the enzyme activity level, the content list of content data having respective patterns of temporal change of the enzyme activity level during reproduction of the content data, wherein the content data is determined in that it has pattern of temporal change opposite to the acquired pattern of temporal change of the acquired enzyme activity level, and reproduce the content data by utilizing a bone-conduction function of the bone-conduction module.