Page "Speech recognition" Paragraph 73

Speech recognition by a machine is a process broken into several phases.

Computationally, it is a problem in which a sound pattern has to be recognized or classified into a category that represents a meaning to a human.

Every acoustic signal can be broken in smaller more basic sub-signals.

As the more complex sound signal is broken into the smaller sub-sounds, different levels are created, where at the top level we have complex sounds, which are made of simpler sounds on lower level, and going to lower levels even more, we create more basic and shorter and simpler sounds.

The lowest level, where the sounds are the most fundamental, a machine would check for simple and more probabilistic rules of what sound should represent.

Once these sounds are put together into more complex sound on upper level, a new set of more deterministic rules should predict what new complex sound should represent.

The most upper level of a deterministic rule should figure out the meaning of complex expressions.

In order to expand our knowledge about speech recognition we need to take into a consideration neural networks.

There are four steps of neural network approaches: