The present technology relates to a signal processing device, a signal processing method, and a program for enabling reproduction of high-quality sounds with a low process load. The signal processing device includes a demultiplexing section that extracts encoded audio signals and overamplitude flags, which have been generated for a plurality of respective panel loudspeakers and each indicate whether overamplitude will occur in the corresponding panel loudspeaker, by demultiplexing encoded data, a decoding section that decodes the encoded audio signals, and an adjustment section that adjusts audio signals to be supplied to the plurality of panel loudspeakers on the basis of the overamplitude flags and audio signals resulting from the decoding. The present technology is applicable to an encoding device and a decoding device.