Noise reduction device and noise reduction system

A noise reduction device comprising:

• a noise detection section configured to detect noise;
• a noise control section configured to generate a control sound signal for reducing the noise detected by the noise detection section at a control center of a control space inside a seat;
• a control sound output section configured to output a control sound on the basis of the control sound signal from the noise control section;
• an error sound detection section configured to detect an error sound by superimposing the noise at the control center with the control sound outputted from the control sound output section;
• and
• a seat detection section configured to detect that a seat is in an actual usage state for noise reduction,
• wherein the noise control section has an identification sound generation section and an identification control section, and
• in identifying an acoustic transfer function that includes a path from the control sound output section to the error sound detection section or the noise detection section by outputting an identification sound from the control sound output section and detecting the identification sound with the error sound detection section or the noise detection section,
• the identification control section is configured to identify the acoustic transfer function by generating the identification sound from the identification sound generation section when the seat detection section has detected that the seat is in the actual usage state for noise reduction.