音频

The current second-generation and third-generation (3G) mobile communication systems operate with narrow audio bandwidth limited to 200-3400Hz.As wireless systems are evolving from voice-telephony dominated services to multimedia and high-speed data services, the introduction of a wider bandwidth of 50–7000 Hz speech codec which provides substantially improved speech quality and naturalness is quite necessary. The Adaptive Multi-rate Wideband speech codec which was selected by 3GPP/ETSI and ITU-T can provide natural, present and comfortable codec speech and have higher intelligence and robustness in wireless systems. A wide range of applications are envisioned for AMR-WB, including ISDN wideband telephony and audio/video teleconferencing,Voice over IP and Internet applications such as IP video conferencing, voice mail, voice chat, broadcast, and voice streaming.

随着现代无线通信特别是多媒体通信的发展，人们对语音通信的质量要求越来越高。3GPP/ETSI TS026和ITU-T 722.2标准确定的自适应宽带语音编解码器AMR-WB具有的低比特率、互操作性和高语音质量，使之不仅能够应用于无线通信领域，而且可广泛应用于其他各种通信系统和平台，包括：VoIP、因特网、PSTN高质量音频会议、音频流、ISDN宽带电话、ISDN可视电话和电视会议等。

Although vocoder can transmitter speech signal at very low bit rate, it does not work well when dealing with audio signal.

在本学位论文中我们设计了一种低码率音频编码器。对于很多不同类型的音频信号，它可以工作在很低的码速率上，虽然此时它所提供的听觉质量不是透明的，人们仍然可以接受。

In this paper, the development of audio watermark is first introduced.

本文介绍了当前音频数字水印技术的发展情况，总结了音频数字水印的分类。

The Editor allows you to perform various operations with audio data such as displaying a waveform image of an audio file, filtering, applying various audio effects.

它使用方便，支持创建编辑保存音频文件，可以进行剪切、复制、删除、粘贴、混合、组合等操作，可以支持所有主要音频格式。

Clipping and DC offset detection and reduction helps you to enhance recording quality with any audio recording device. You can cut, delete, fade in/out, copy, amplify and normalize the recorded waveform with a built-in audio editor and save it into MP3 and WAV format.

Steady Recorder还带有一个内建的简单音频编辑器，可以进行剪切、删除，淡入淡出、复制，放大或正常化波形等操作，并可以将录制后的音频保存为MP3或WAV格式，支持MP3 VBR。

The audio waveform is divided into several pieces according to the pitch period, and then the successive pieces with the same semitone arc grouped into one segment. The scaling operations arc performed on all these segments by the pre defined scaling factor.

首先利用基音分析技术将整个音频波形分割为若干基音周期，然后以半音为单位将连续的基音周期组织成音频段落，并在各个段落内部按指定比例进行缩放。

Awave Audio is the easiest way to convert between different audio file formats.

awave音频是最简单的方式转换之间不同的音频文件格式。

Software Description: About Awave Audio, This program allows you to perform batch audio conversions between 90 different audio file formats.

Awave Audio 这个程序允许你迅速地和容易地执行进到超过 30 种不同音频的格式的一批音频信号转换。

A bewilderingly diverse variety of lifestyles, from parasites to predators

进入有音频下载的文章页面，点击带有下划线的文章标题，可保存和直接播放；用鼠标右键保存，可下载保存音频。

The 92HD83 single-chip audio system is a low power optimized, high fidelity, 6-channel audio codec with integrated speaker amplifier, dual capless headphone amplifier, and low drop out voltage regulator.

IDT公司的92HD83是六路PC音频系统方案，具有最佳的功耗，集成了六路音频CODEC和扬声器放大器，双路无电容的耳机放大器和低压降电压稳压器。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。