混响 is a result of 多 反射 A 声音 波 in an enclosed or semi-enclosed 环境 will be broken up as it is bounced back and forth among the 反射 表面 混响 is in 效果（效应） a multiplicity of 回声 whose 速度 of 重复 is too quick for them to be 感知（认为） as separate from one another W C Sabine 确定（建立） the official period of 混响 as the 时间 required by a 声音 in a 空间 to 减少 to one-millionth of its 原始/原创 强度/ i e for its 强度 电平/级别 to change by -60 dB However 最小 the 混响 品质 of any 空间 whether enclosed or 不 helps to 定义 the way in which it is 感知（认为） Although it may 不 be realised 知觉 混响 is one of many cues used by a 听众 for orientation in a 特定 空间 The 比 of 直达 to 混响 声音 is also an 重要 cue for the 感知 of 深度 and 距离 混响 will also 增加 the 周围 噪音 电平/级别 and apparent 响度 of 声音 within a 空间 an 重要 因素 to consider in acoustic 设计

人工 混响 is 传统 产生 by 手段(意味着) of a 混响 室 or 回声 室 多 磁带 回声 or more commonly by exciting a metal spring or plate at one end and picking up the 延迟 信号 at another point However 数字 处理 设备 and 计算机 技术 have been 发展 in recent years that allow a good 模拟 of naturally 产生 混响 These 系统 allow for a variable 比 of 直达 to 反射 声音 and some include both global 混响 i e 反射 声音 from all directions and local 混响 i e that coming from the 方向 of the 声音 源 源 Barry Truax - Handbook for Acoustic 生态学 CD-ROM Edition Cambridge Street 出版 1999 - CSR-CDR 9901