Sounds as a Search Query
Hearing is one of the most important evolutionary adaptations organisms have developed. Predators depend on sound to catch their prey while the prey use noise to avoid the predators, but sound is just compressed air waves, so how can creatures know which sounds are indicative of predators and which are wind and rain? New research shows that specific neurons in the brain react differently to different sounds. The neurons control activity of other neurons in the brain that signal different reactions, and adapt to categorize sounds. The noises that a specific organism encounters regularly, such as ambient noise are given a low priority, which causes very little reaction from the neuron, but unexpected noises demand more attention, so there is higher activity in the neurons after exposure to those. This way, the organism reacts appropriately to stimulus that requires action rather than alerting it at the slightest noise.
This mechanism is similar to the way search engines operate and categorize their results. Take a sample of noise for a search query. Search engines such as Google put less emphasis on the words in the query that appear most commonly in the language. Words such as “a,” “the,” “and,” and “to” carry little meaning in the overall search, so engines will marginalize them and put more importance on the other words. In fact, one can usually enter a query into a search engine while omitting these articles and conjunctions and often obtain very similar results. This is search engine reacting appropriately to its stimulus, much like animals react to sounds, but in this case the stimulus is a search. Both filter out irrelevant information and adapt to react appropriately to each respective stimulus.
Source: http://www.uphs.upenn.edu/news/News_Releases/2015/10/geffen/