Echo chamber refers to a person who totally, obsequiously agrees with everything another person says, just like an echo chamber that is used to produce echoing sounds, usually for recording purposes.
“回声筒”指的是某人为了献媚而完全同意另一个人所说的一切，就像录音时用来制造回声效果的回声筒一样。
For example:
During the meeting my boss Jeremy calls on Jason, who’s a well-known management echo chamber to ask if Jason thinks the Company’s new and much stricter Internet policy is a fair one.
开会的时候，我的老板杰瑞米让杰森发表意见，问他公司新推出的更加严格的网络政策是否公平，我们都知道杰森是管理层的“回声筒”。
扩展阅读：
“随便、还行”英语这么说
