A wireless sound-emitting device includes a housing adapted to be coupled to a wall at a source of electric power, a loudspeaker positioned at a periphery of the housing, a control module outputting an electric audio signal to the at least one loudspeaker, and a wireless communications module in electrical communication with the control module. The loudspeaker emits acoustic signals in a direction parallel to the wall, when the housing is coupled to the wall, with the acoustic signals reflecting off the wall. The device may produce a sound masking noise or play a sound recorded on an internal memory. The device may include an electric plug or be adapted to replace an electric outlet faceplate. The device may have electric pass-through outlets and may be powered by the source of electric power. The device may be controlled remotely, for example via an Internet of Things (IoT) platform.