A sound processing device program that enables a sound signal adapted to an intended use to be output is provided. The sound processing device includes a signal processing part that processes a sound signal picked up by a microphone, and generates a recording sound signal to be recorded in a recording device, and generates an amplification sound signal different from the recording sound signal to be output from a speaker. The sound processing device can be applied to, for example, a sound amplification system that performs off-microphone sound amplification.