According to an embodiment, an acoustic output apparatus includes an acquisition unit and an output unit. The acquisition unit acquires non-stationary sound data that masks an operating sound, in which the operating sound is based on an operation of the operation unit. The output unit outputs a non-stationary sound based on the sound data acquired by the acquisition unit during occurrence of the operating sound.

A noise reducing structure includes a first resonance tube that extends in a first direction, that takes in from a sound absorbing opening portion a sound wave that is generated from a noise source, and that causes the sound wave to resonate to reduce leakage to outside; and a second resonance tube that extends in a second direction differing from the first direction, and that, along with the first resonance tube, causes the sound wave that is generated from the noise source to resonate to reduce the leakage to the outside.

According to an embodiment, an acoustic output apparatus includes an acquisition unit and an output unit. The acquisition unit acquires non-stationary sound data that masks an operating sound, in which the operating sound is based on an operation of the operation unit. The output unit outputs a non-stationary sound based on the sound data acquired by the acquisition unit during occurrence of the operating sound.

A paper sheet transporting apparatus includes a transporting guide through which a paper sheet is transported and a sound propagation guide to transmit sound that is provided separately from the transporting guide by connecting two positions separated from each other on the transporting guide. When a difference between a length between the two positions of the transporting guide and a length of the sound propagation guide connecting the two positions is defined as L(m), m=(2n1) (n is an integer) is satisfied, and a wavelength of a sound deadening symmetrical sound is defined as (m), L=m.Math./2 is satisfied.

A paper sheet transporting apparatus includes a transporting guide through which a paper sheet is transported and a sound propagation guide to transmit sound that is provided separately from the transporting guide by connecting two positions separated from each other on the transporting guide. When a difference between a length between the two positions of the transporting guide and a length of the sound propagation guide connecting the two positions is defined as L(m), m=(2n1) (n is an integer) is satisfied, and a wavelength of a sound deadening symmetrical sound is defined as (m), L=m.Math./2 is satisfied.

A noise reducing structure includes a first resonance tube that extends in a first direction, that takes in from a sound absorbing opening portion a sound wave that is generated from a noise source, and that causes the sound wave to resonate to reduce leakage to outside; and a second resonance tube that extends in a second direction differing from the first direction, and that, along with the first resonance tube, causes the sound wave that is generated from the noise source to resonate to reduce the leakage to the outside.

An image processing apparatus includes circuitry configured to obtain audio data of audio collected through a microphone, determine whether the audio data has a noise level equal to or less than a threshold to generate a determination result, record the audio data when the determination result indicates that the noise level of the audio data is equal to or less than the threshold, and add the recorded audio data to image data.