Wave File Compression Codecs Compared Audio Compression Manager This is a reference to compare the audio quality and compression bitrates of the different wave compression codecs available for ".wav" and ".dct" files using the audio compression manager including PCM, GSM, ADPCM, CELP, SBC, TrueSpeech and MPEG Layer-3. Note: The Audio Compression Manager (ACM) is used for recording to .wav (wave) or .dct (dictation) files. For other file formats, please start with the Sound File Formats page. The ACM is used by: The audio file compression formats listed on this page are low bitrate speech formats. Higher bitrate music and broadcast voice formats are not listed. You can listen to samples of each audio format by clicking on the "Sample" link. Format | Bitrate | 1 min = | Sample | | 11,025Hz 16bit PCM | 176.4kbs | 1292k | 11k16bitpcm.wav | | 8000Hz 16bit PCM | 128kbs | 937.5k | 8k16bitpcm.wav | | 11,025Hz 8bit PCM | 88.2kbs | 646k | 11k8bitpcm.wav | | 11,025Hz u-Law | 88.2kbs | 646k | 11kulaw.wav | | 8,000Hz 8bit PCM | 64kbs | 468.8k | 8k8bitpcm.wav | 8,000Hz u-Law
* toll quality telephone | 64kbs | 468.8k | 8kulaw.wav | | 11,025Hz 4bit ADPCM | 44.1kbs | 323k | 11kadpcm.wav | | 8000Hz 4bit ADPCM | 32kbs | 234.4k | 8kadpcm.wav | | 11,025Hz GSM6.10 | 18kbs | 131.8k | 11kgsm.wav | | 8000Hz Mp3 16k | 16kbs | 117k | 8kmp316.wav | 8,000Hz GSM6.10
* cell phone quality | 13kbs | 102.5k | 8kgsm.wav | | 8000Hz Lernout & Hauspie SBC 12k | 12.0kbs | 87.9k | 8ksbc12.wav | | 8,000Hz DSP Group TrueSpeech | 9kbs | 65.9k | 8ktruespeech.wav | | 8000Hz Mp3 8k | 8kbs | 60k | 8kmp38.wav | | 8,000Hz Lernout & Hauspie CELP | 4.8kbs | 35k | 8kcelp.wav | |
Comments The above are wave files - even if they have the mp3 codec they will have the ".wav" or ".dct" extension. For a broader overview of other file formats, please see the Sound File Formats page. Recommended Codec NCH Software currently recommends GSM6.10 8000Hz for voice recording. Problem Formats The ACM codec shipped with Windows 2000/XP called "Microsoft G.723.1" has a bug which means it cannot be used for encoding / recording. Please do not attempt to use this format. Discussion Forum If you have any questions in ACM codecs or are generally interested please see the Sound Formats Discussion Forum. Software that Support ACM A number of the NCH Software professional audio software applications include the Audio Compression Manager: |
