Image forming apparatus including a sound sensor to determine cleaning failure

An image forming apparatus comprising:

• an image carrier that carries a toner image;
• a transfer unit that transfers the toner image from a surface of the image carrier to a transfer medium;
• a cleaning blade that cleans residual toner adhered on the surface while abutting with the surface that has passed the transfer unit;
• a sound sensor that collects a sound generated inside a casing of the image forming apparatus;
• and
• a determining unit that determines, based on the sound collected by the sound sensor, whether cleaning failure has occurred in the cleaning blade based on at least intensity of a first sound component that is a sound component of a first frequency and intensity of a second sound component that is a sound component of a second frequency different from the first frequency.