PCM: PCM is not an audio codec, but simply an uncompressed format. This format takes up a high amount of space, but offers the best sound quality. As it’s not compressed, and will not have to be decompressed like codecs, it requires very little CPU processing power.

When to use: With short and repetitive audio files, to reduce strain on the processing power, or high fidelity sounds.

	When importing an Audio file into Wwise, it has to be in the file format '.WAV' using the PCM audio format. This ensures a high quality source that can later be converted into other formats or remain PCM.

Vorbis: One of the most popular audio codecs in the interactive audio sector because it preserves sound quality at very low bit rates compared to other formats. In Wwise, this format is highly optimized for interactive media and gaming platforms.

When to use: Good for the majority of sounds in your project, but avoid using this format on audio files with high repetition rates because it requires some processing power to decompress. Some ‘noisy’ sounds like Rock destruction in the Dungeon are perfect for highly compressed Vorbis, as the artifacts induced by compression won’t be perceived as low quality to the user.

	The Vorbis codec requires Seek tables if you’d like to pause, resume, or loop within the audio file. Learn more about Seek tables in Lesson 3.

WEM Opus: An excellent format for quality in relation to size. The perceived quality is slightly higher than Vorbis, but uses more CPU. It does not require any seek tables for seeking or looping.

When to use: WEM Opus is a great choice for non-looping audio sources, such as dialogue, or long audio sources like ambiences, and it complements Vorbis well when file size demands are particularly strict. It works best with sounds that las longer than 200ms.

ADPCM: ADPCM offers a compression ratio of 3:1 compared to PCM. It uses almost no CPU in comparison to Vorbis, which makes it a good codec in many cases.

When to use: Ambiences or other SFX where you’d like to free up more memory than PCM. It’s a good alternative to Vorbis for mobile devices in order to save CPU, and it saves runtime memory over PCM.