传统录音机和数码录音笔在信道中的差异

语音是重要的法庭证据。随着科学技术的进步,各种各样的语音采集设备出现在人们的日常生活中。从传统的录音机到数字录音笔、手机、MP3,语音采集经历了由模拟信号到数字信号的转换过程。不同的采集设备和方法会造成语音的信道差异。传递语音信号的通道,如：传统录音机和数码录音笔由于各自的频率响应性能不同,对信号施加的影响也不同。传统录音机传递的是连续变化的模拟信号,数码录音笔传递的则是以有限个＂1＂和＂0＂的代码组合成为信息的数字信号,两者是现在普遍应用的两种信号模式。研究表明：信号通道对于语音识别,特别是自动语音识别的影响是明显的,但是对于图谱视觉检验的影响、影响的程度如何还尚待进一步的深入研究。

The Differences in Transmission Channels of Traditional Tape Recorders and Digital Recorders

Voice is one of the most important court evidences.With the development of science and technology,various voice recording equipments appear in people＇s daily life.From the traditional tape recorders to the digital recorders,mobile phones and MP3,the voice gathering has experienced the development from the analogical signals to digital signals.The different recording equipments and methods will result in.The transmission channels,such as traditional tape recorders and digital recorders,have different effects on voice signals due to different functions of response performances.The traditional tape recorder transmits simulate signals which change continuously while the digital recorder transmits the digital signal from the limited code combination of ＂1＂ and ＂0＂.Both of them are common models of signaling at present.Previous studies indicate that the effect of signal channel on speech recognition is obvious,especially on automatic speaker recognition.But there is few further study on its effects on visual examination of speech spectrum.