The "Raw" PCM formats are generic formats not readily associated with a card or system manufacturer. Under "Raw" formats you will find only headerless formats, sometimes at unusual sampling rates. For instance, A-law is a companding law that is always used at 8,000 samples per second in the telephony world. If you select "Raw PCM Formats" we will in fact allow you to produce A-law files at any frequency from 6 KHz to 64 KHz; the same is true for the other "raw" formats. The "raw" formats are provided for knowledgeable users; use them with circumspection.
16-bit and 8-bit Linear PCM
Linear PCM data is the pure, uncompressed and uncompanded binary code representation of the value of an analogue signal (e.g. voice) after digitization.
Vox Studio can record 8 and 16-bit linear PCM from 6,000 up to 48,000 samples per second. Of course, this is overkill for most standard telephony applications.
Vox Studio uses a high-resolution linear representation of signals internally to ensure the best possible conversion and filtering results. This is transparent to you, the user, but should indicate how much care is taken of your precious sound samples when we compress, compand, translate and otherwise massage them.
The more bits that are utilized, the more accurate the signal representation will be. 8-bit PCM represents signals digitized into 256 discrete levels. 16-bit PCM represents signals digitized into 65,536 discrete levels. The higher the resolution, the more hi-fi your reproduced sound gets. Also, the more samples that are taken per second, the better the reproduced sound gets. Obviously, 16-bit linear PCM sampled at 48 KHz represents a data stream of 768,600 bps, 32 times more than 6 KHz ADPCM at 4 bits! Be careful when you select extreme resolutions, you may fill your hard disk much faster than you expect.
We strongly advise against the use of 8-bit resolution master recordings, even for telephony, unless absolutely required. Use 16-bit resolution wherever possible.