This quote for Wikipedia is not fully accurate. Yet is represents the ideas about recording speech for storage on a digital media.
Speech coding differs from other forms of audio coding in that speech is a much simpler signal than most other audio signals, and a lot more statistical information is available about the properties of speech. As a result, some auditory information which is relevant in audio coding can be unnecessary in the speech coding context. In speech coding, the most important criterion is preservation of intelligibility and "pleasantness" of speech, with a constrained amount of transmitted data.
That is not true. Speech is one of the most complex vocal forms in nature. But the human year can understand speech when it is very distorted. This is because speech has considerable redundancy.
A 10 to one reduction of data is feasible in speech processing to reduce bandwidth and size. Example. 128 bps MP3 sounds very nice to most listeners. *At 128 bps there already is much reduction.) But that same speech could be reduced to 32 bps and be ineligible, but annoying. It has a harsh artificial sound. But for some speakers, it might be considered an improvement.
Audio Files for Dummies
. (Don;t buy the book.)
He give some information, but fails to explain that compression can mean three different things and are not related. He means reduction of size after speech has been digitally encoded.
I would prefer to call it reduction of digital bandwidth of encoded audio.
To reduce files size with not loss of integrity, use the ZIP format. Otherwise reducing digital bandwidth of audio is almost always a reduction in integrity. Few exceptions.