A reproducing apparatus comprising: a display configured to reproduce video data; a speaker configured to reproduce audio data; a viewpoint detector configured to: detect, as a detection signal, whether a target of a viewpoint of a user is directed to the display or an object different from the display, and send the detection signal; a discriminating unit configured to: receive the detection signal, determine, from the detection signal, a ratio of a duration of time at which the user is watching the display for a predetermined interval of time, discriminate, on the basis of the ratio a monitoring state, a while-watching state, or a concentration state, wherein the monitoring state is a state where the ratio is equal to or higher than a first threshold, the while-watching state is a state where the ratio is lower than the first threshold and equal to or higher than a second threshold, the concentration state is a state where the ratio is lower than the second threshold, and generate a control signal on the basis of the discrimination result; and an audio controller configured to set, on the basis of the control signal, a sound volume level of the speaker to: an optimum level, when the degree of the interest corresponds to the monitoring state, a minimum level, when the degree of the interest corresponds to the concentration state, or to an intermediate level between the optimum level and the minimum level, when the degree of the interest corresponds to the while-watching state. a display configured to reproduce video data; a speaker configured to reproduce audio data; a viewpoint detector configured to: detect, as a detection signal, whether a target of a viewpoint of a user is directed to the display or an object different from the display, and send the detection signal; detect, as a detection signal, whether a target of a viewpoint of a user is directed to the display or an object different from the display, and send the detection signal; a discriminating unit configured to: receive the detection signal, determine, from the detection signal, a ratio of a duration of time at which the user is watching the display for a predetermined interval of time, discriminate, on the basis of the ratio a monitoring state, a while-watching state, or a concentration state, wherein the monitoring state is a state where the ratio is equal to or higher than a first threshold, the while-watching state is a state where the ratio is lower than the first threshold and equal to or higher than a second threshold, the concentration state is a state where the ratio is lower than the second threshold, and generate a control signal on the basis of the discrimination result; and receive the detection signal, determine, from the detection signal, a ratio of a duration of time at which the user is watching the display for a predetermined interval of time, discriminate, on the basis of the ratio a monitoring state, a while-watching state, or a concentration state, wherein the monitoring state is a state where the ratio is equal to or higher than a first threshold, the while-watching state is a state where the ratio is lower than the first threshold and equal to or higher than a second threshold, the concentration state is a state where the ratio is lower than the second threshold, and the monitoring state is a state where the ratio is equal to or higher than a first threshold, the while-watching state is a state where the ratio is lower than the first threshold and equal to or higher than a second threshold, the concentration state is a state where the ratio is lower than the second threshold, and generate a control signal on the basis of the discrimination result; and an audio controller configured to set, on the basis of the control signal, a sound volume level of the speaker to: an optimum level, when the degree of the interest corresponds to the monitoring state, a minimum level, when the degree of the interest corresponds to the concentration state, or to an intermediate level between the optimum level and the minimum level, when the degree of the interest corresponds to the while-watching state. an optimum level, when the degree of the interest corresponds to the monitoring state, a minimum level, when the degree of the interest corresponds to the concentration state, or to an intermediate level between the optimum level and the minimum level, when the degree of the interest corresponds to the while-watching state.