High-Efficiency Advanced Audio Encoding (HE-AAC)—often referred to as aacPlus—is a lossy compression scheme for digital audio. HE-AAC is optimized for use with streaming audio applications that require low bit rates, such as Internet radio or streaming music services.
What is AAC, HE-AAC and xHE-AAC?
There are two versions of this compression scheme: HE-AAC and HE-AAC v2. The second version uses improved features and is more standardized than the first.
In digital music, the HE-AAC format is supported and used in several ways. These include:
Coding Technologies, the developers of HE-AAC, first created the compression system by integrating Spectral Band Replication (SBR) into AAC-LC (low complexity AAC). The trade name the company uses is CT-aacPlus. SBR, also developed by Coding Technologies, is used to enhance audio by efficiently encoding higher frequencies. This coding enhancement technology, which is particularly good for streaming voice transmissions, reproduces higher frequencies by transposing lower frequencies.
