Apparatuses and methods are provided useful to monitoring conditions on shelves intended to hold merchandise. There is provided a system for monitoring conditions on shelves including: a shelf for holding merchandise, the shelf being moveable between a first position and a second position; a sound emitter configured to produce a sound in response to movement of the shelf from the first position to the second position; an image sensor configured to capture an image of the interior of the shelf when in the second position; an audio sensor configured to detect the sound indicating the shelf is being moved from the first position to the second position; and a control circuit configured to receive a signal from the audio sensor and to cooperate with the image sensor in response to the signal to capture the image of the shelf when in the second position.