音频编解码器是指能编码或解码音频数字数据流的设备或计算机进程。

在软件层面，音频编解码器是一个执行算法的计算机进程，能压缩与解压缩数字音频数据到音频文档或流媒体音频编码格式。该算法的目的是保证质量的前提下使用最少的比特表示高保真音频信号。这可以有效地减少存储空间和传输已存储音频文档所需的带宽。大多数编解码器是实现为一个具有接口的函式库供一个或多个媒体播放器使用。

在硬件层面，音频编解码器指一个能编码模拟音频到数字音频和解码数字音频到模拟音频的独立设备。换种说法，它包含运行在同样时钟的模数转换器（ADC）和数模转换器（DAC）。这在声卡中被使用以支持音频输入和输出。

An audio codec is a device or computer program capable of coding or decoding a digital data stream of audio.

In software, an audio codec is a computer program implementing an algorithm that compresses and decompresses digital audio data according to a given audio file or streaming media audio coding format. The objective of the algorithm is to represent the high-fidelity audio signal with minimum number of bits while retaining the quality. This can effectively reduce the storage space and the bandwidth required for transmission of the stored audio file. Most codecs are implemented as libraries which interface to one or more multimedia players.