Earphone and terminal device

A terminal device, comprising an earphone, wherein the earphone comprises:

• a housing having a cavity structure disposed within, and a sound output port in communication with the cavity structure;
• a first sound transducer, a second sound transducer, and a third sound transducer disposed in the cavity structure, wherein a sound production frequency of the second sound transducer is greater than a sound production frequency of the first sound transducer and is less than a sound production frequency of the third sound transducer;
• and
• the third sound transducer is a micro-electro-mechanical system located between the first sound transducer and the sound output port,
• a surface of the first sound transducer facing the sound output port and a part of an inner wall of the cavity structure form a front cavity,
• a surface of the first sound transducer facing away from the sound output port and a part of the inner wall of the cavity structure form a rear cavity separated from the front cavity,
• the third sound transducer is disposed in the front cavity,
• a surface of the third sound transducer facing the sound output port and a part of an inner wall of the front cavity enclose a first sound output channel in communication with the sound output port, and
• a part of the inner wall of the front cavity, a surface of the micro-electro-mechanical system facing away from the sound output port, and the surface of the first sound transducer facing the sound output port jointly enclose a middle cavity in communication with the first sound output channel within the cavity structure of the housing.