But – crucially – the waves coming from the speaker pass through a 'hologram plate'.

但是——至关重要的是——来自扬声器的波通过“全息图板”。

This type of effect has been achieved before using an array of speakers (without the hologram plate).

在使用扬声器阵列（没有全息图板）之前已经实现了这种效果。

First, the team plugs the dove design into a computer which works out the structure of the hologram plate.

首先，该团队将鸽子设计插入计算机，计算出全息图板的结构。

By comparison, combining one speaker with a single 3D printed hologram plate is equivalent to an array of about 20,000 speakers.

相比之下，将一个扬声器与单个 3D 打印全息图板相结合，相当于约 20,000 个扬声器的阵列。