MySQL beta at CHEARSdotinfo co uk

Lesson 8

The program 材料 we are interested in 聆 to or 錄/录 we shall call the 信号 Any 声波 that 干涉 with enjoyment or 理解 of the 信号 is called 噪 If the 信号 主宰 excellent But if 噪 主宰 the 信号 is useless

The 相对 强度/ of the 信号 比较 to that of the 噪 is a very 重要 因素 in all 通讯 系统 We even have a name for it the 信噪 比 If the desired 信号 主宰 the 信噪 比 is 高 and all is well

At a 信噪 比 of 40 dB it becomes more difficult to 听 the 噪

混响 is a kind of 噪 so we can 期望 white 噪 to 影响 the 理解 of 语 in a 类似 way

The inevitable 噪 that often 干涉 with the desired 信号 is less 熟悉 to us

电子 current 流动 in every 晶体管 every 作品 of wire 生成 a 嘶嘶声 声波 like we have just 听 Fortunately it is quite 弱 but certain 电路 faults can make it a problem

无线电 频率 信号 such as those from nearby 无线电 and 电视 广播 站 can easily 穿透 為耳/音频 电路 if there is improper shielding

The 噪 of heating ventilating and air 条件 设备 is often of 高 enough 级 to 降级 a 錄/录 or interfere with 聆

In 聆 to 现场 or reproduced 樂/乐 or 语 信号 品质 can be 影响 by 环境 噪 The mere 临场 of 人 in an 听众 results in 噪 of 呼吸 动作 coughing rustling paper