A content reproduction device including: a microphone that collects noise in the surroundings of a casing; a feature amount extractor that extracts a plurality of feature amounts; a distance calculator that calculates an intervector distance between the extracted feature amount vector and a feature amount vector with the same dimensions which is set in advance as a feature amount of a waveform of a music signal; a determinator that determines whether or not music is included in the sounds collected by the microphone; a processor that processes the signal of the sounds collected by the microphone to change the volume or frequency characteristics of the sounds collected by the microphone; and an adder that adds and outputs the signal of the sounds collected by the microphone and the signal of sounds of reproduced content.