Japanese sound symbolism

Japanese has a large inventory of sound symbolic or mimetic words, known in linguistics as ideophones. Sound symbolic words are found in written as well as spoken Japanese. Known popularly as onomatopoeia, these words are not just imitative of sounds but cover a much wider range of meanings; indeed, many sound-symbolic words in Japanese are for things that don't make any noise originally, most clearly demonstrated by , meaning "silently".
Categories.
The sound-symbolic words of Japanese can be classified into four main categories:
These divisions are not always drawn: sound-symbolism may be referred to generally as onomatopoeia (though strictly this refers to imitative sounds, phonomimes); phonomimes may not be distinguished as animate/inanimate, both being referred to as "giseigo"; and both phenomimes and psychomimes may be referred to as "gitaigo".
In Japanese grammar, sound-symbolic words primarily function as adverbs, though they can also function as verbs (verbal adverbs) with the auxiliary verb , often in the continuous/progressive form , and as adjectives (participle) with the perfective form of this verb . Just like ideophones in many other languages, they are often introduced by a quotative complementizer . Most sound symbolic words can be applied to only a handful of verbs or adjectives. In the examples below, the classified verb or adjective is placed in square brackets.
Note that, unlike the other examples, "doki doki" is the onomatopoeic sound of two beats of a heart.
Other types.
In their "Dictionary of Basic Japanese Grammar", Seiichi Makino and Michio Tsutsui point out several other types of sound symbolism in Japanese, that relate phonemes and psychological states. For example, the nasal sound gives a more personal and speaker-oriented impression than the velars and ; this contrast can be easily noticed in pairs of synonyms such as and which both mean "because", but with the first being perceived as more subjective. This relationship can be correlated with phenomimes containing nasal and velar sounds: While phenomimes containing nasals give the feeling of tactuality and warmth, those containing velars tend to represent hardness, sharpness, and suddenness.
Similarly, i-type adjectives that contain the fricative in the group "shi" tend to represent human emotive states, such as in the words , , , and . This too is correlated with those phenomimes and psychomimes containing the same fricative sound, for example and .
The use of the gemination can create a more emphatic or emotive version of a word, as in the following pairs of words: , , , and many others.