Psychoacoustics—that is the branch of psychology concerned with the perception of sound and its physiological effects.

心理声——这是心理的一个分支， 研究声音的感知及其生理效应。

In psychoacoustic research, so much of the things that we know about the sound world were developed either for telephony or for the military.

在心理声研究领域，们对声音世界的诸多认知，大多源自于为电话通讯或军事用途而进行的研发。

This psychoacoustic algorithm finds elements in the audio that have exceptionally low volume sounds, very high-pitched sounds, or sounds very close together which the MP3 compression discards, thereby saving space and making it a lossy compression format.

这种心理声法会找到音频中音量极低的声音、音调极高或非常接近的声音，这些声音被MP3压缩丢弃，从而节省空间，使其成为有损压缩格式。