Sounding device and mobile terminal

A sounding device, comprising:

• a housing body with an accommodating space;
• a speaker unit accommodated in the accommodating space;
• a one-way inlet valve and a one-way outlet valve fixed on the housing body;
• wherein
• the speaker unit comprises a diaphragm for partitioning the accommodating space into a front cavity and a back cavity;
• the one-way inlet valve communicates the outside and the back cavity for introducing air into the back cavity when the volume of the back cavity is increased through vibration of the diaphragm;
• the one-way outlet valve communicates with the back cavity and the outside for discharging the air in the back cavity outside when the volume of the back cavity is reduced through the vibration of the diaphragm;
• a first through hole communicating with the outside and the back cavity is formed in the housing body;
• the one-way inlet valve comprises a first bracket fixed at an inner side of the housing body and completely covering the first through hole, and a first diaphragm attached to one side, far away from the first through hole with respect to the first bracket;
• the first bracket comprises a first bracket body fixed at the inner side of the housing body, and a first air channel and second air channels penetrating through the first bracket body respectively;
• the first air channel communicates with the first through hole;
• the second air channels are arranged around the first air channel at intervals;
• the second air channels extend to the periphery of the first bracket body and communicate with the back cavity;
• the first diaphragm comprises a first vibration part capable of moving up and down relative to the first bracket body and defining an intake space together with the first bracket body when moving to be spaced apart from the first bracket body, a first folded ring part extending from the periphery of the first vibration part, and a first fixation part diffusing and extending outwards from one end, far away from the first vibration part with respect to the first folded ring part;
• the first fixation part is attached to and fixed on the first bracket body and covers one part of the second air channels;
• the first fixation part, the second air channels and the housing body cooperatively define an air inlet passage communicating with the back cavity and the intake space;
• and the first air channel communicates with the intake space and the first through hole.