Sound gathering device for voiceprint monitoring and preparation method

A preparation method for preparing a sound gathering device, wherein the sound gathering device is a cone structure and comprises a front end portion, and a rear end portion, the front end portion is trumpet-shaped, an inner wall surface of the front end portion is configured to present a pattern array of microstructures, and the pattern array of microstructures is formed by laser etching;

• a sound wave frequency monitored by the sound gathering device is 50 Hz˜10 kHz, and a sound wave enters the sound gathering device from an entrance of the front end portion, is reflected through the pattern array of microstructures on the inner wall surface of the front end portion, and is transmitted from an exit of the rear end portion, and a sound pressure of the exit of the rear end portion is 4 times˜8 times a sound pressure of the entrance of the front end portion;
• where the method comprising:
• prefabricating a sound gathering device with a cone structure, wherein the sound gathering device comprises a front end portion and a rear end portion;
• planning a path where a laser beam travels based on a pattern array of an inner wall surface of the front end portion of the sound gathering device;
• setting a parameter value of a laser, wherein a parameter category of the laser comprises a laser pulse width, a laser wavelength, a power range and a scan speed;
• building a laser focusing device according to a laser beam focusing manner to focus a laser beam emitted by the laser;
• and
• starting the laser, and performing laser etching on the inner wall surface of the front end portion to prepare a microstructure of an inner surface of the sound gathering device.