There are two types of echo words. The first ones are the word really intended to simulate the sound. Typical sound of laughter is "Ha! ha! ha!". This is the first type. The second ones are the words intended to simulate the sound feeling-wise. The clean water in a stream flows "sarasara". The stream do not sound like this or even not audible. A butterfly flies "hirahira". A drunken man walks "furafura". Today I worked too hard, now I am "furafura". These are the second type. Often the difference between the first type and the second type is subtle. So, here I treat them equally.

Now, how japanese laugh?

Ha! ha! ha! A! ha! ha!	Thought most ordinary laughter especially for males.
Kya! ha! ha!	Childish "Ha! ha! ha!
Ho-ho-ho O-ho-ho	Thought most ordinary laughter for females. Females who laugh with mouth open largely is thought not modest. Different from the "Ho! ho! ho!" of Santa Claus. Often ladies laugh hiding the mouth with their hands. Ladies are thought should laugh modestly and amiably.
Wa! ha! ha! Gwa! ha! ha!	Roaring laughter. Ladies are thought not to laugh like this even if they do when no one is looking them. My dear often laughs "Wa! ha! ha!" at home. "Gwa! ha! ha! is a variation often used as the laughter of baddie hero boasting his victory in comics.
Kara-kara	He laughed "kara-kara". It is nothing difficult. Rely on me!
Kusu-kusu	Some girls are laughing "kusukusu" looking at me. I feel something funny is on me. In reality, they are paying no attention to me. They do not pronounce "kusukuse". It is the feeling-wise translation of their laughter.
Gera-gera Geta-geta	Laughter with no modesty often contain the meaning of scorn. They laughed "gera-gera" at his dull joke.
He! he! he! E! he! he! Fu! fu! fu! U! fu! fu!	A sly laughter. "He! he! he!" I sold that one at twice the value. "E! he! he!", "Fu! fu! fu!" and "U! fu! fu!" are similar variations.
Fu-fu-fu U-fu-fu He-he-he	Similar to "fu! fu! fu!". But he is trying to hid the laughter. He probably succeeded to trap his opponent secretly. "Hehehe" is almost the same with "Fu-fu-fu" but with less intent of hiding. Now the two are beginning something enjoyable secretly. She can not stop laughing and laughed "U-fu-fu" in low voice not to be heard by others.
Ku-ku-ku Kutsu-kutsu	Restrained laughter similar to "Fu-fu-fu" with no malicious vulgar intent. She is laughing "kstsu-kutsu" alone probably recalling something pleasant or reading a comics. Who laugh loud alone are rare.
Hera-hera Kera-kera	Even though I scold him strictly, he doesn't mind, laughing "hera-hera". This is a feeling-wise echo word. She doesn't mind laughing "kera-kera". There is no rule forbidding female to laugh "hera-hera" but not the typical.
Hi! hi! hi! I! hi! hi! U! hi! hi!	"Hi! hi! hi!" I know the color of her panties. A vulgar laughter.
U! shi! shi!	Most vulgar laughter. Now she is on a tight leash. How enjoyable tonight will be alone with her, "U! shi! shi!
Kya! Kya!	Typically laughter of baby or junior. Youth can laugh "Kya! kya!" mostly girls. Girls often laugh "Kyaa! kyaa!" in most noisy way. If a single but loud "KYAA" is heard, it is a scream of a female frightened to death.
Keta-keta	Immodest laughter. She laughs "keta-keta" not taking into the consideration of the situation.
Koro-koro	A decent and pleasant laughter. Males never laugh "koro-koro". Ladies speak "koro-koro" and laugh "koro-koro" like a ball rolling. Balls roll "koro-koro".
Ke! ke! ke!	A laughter of scorn mostly seen in comics. "Ke1 ke! ke!", that guy got the gate again.
Niko-niko Nikkori Niko! N!!	Typical silent joyful smile. He is "niko-niko" getting a new toy. She went through with her friends and seeing me she smiled "Niko!". He was talking to other parson and seeing me, he smiled "Ni!" to me. I knew what he meant. Probably European add winking. Winking is not common in Japan. Some people feel difficulty of winking.
Nita-Nita Niyari Niya!	Kind of silent "Hi! hi! hi!" or "Fu! fu! fu!" or a little malicious "Nikkori" and "Niko".

    There are a lot of variations because echo words are free to make words for anyone anytime.
    Now I wonder if the above introduced echo words and their associated situation are peculiar for Japanese or they are rather common among other nations in the meaning of feeling-wise. If you know web site describing "How American laugh?" or like this, please let me know. I will set links to those web sites.

The echo words which the author like most.

Soyo-Soyo	The wind in early summer blow my cheeks "soyo-soyo" comfortably.
Sara-Sara	The clean water in a brook flows "sara-sara".
Saya-Saya	A decent lady walks "saya-saya" with sound of rubbing clothe.
Suya-Suya	A baby is sleeping "suya-suya" happily".
Kira-Kira	The stars in the sky blink "kira-kira".
Chira-Chira	Snow flakes fall "chira-chira" flickering. The legs of a girl seen "chira-chira" when the wind flaps her skirt is charming. In this case "chirari" is more often used "chirarism":a "janglish" is often used. In "Ukiyoe"s it is often seen. see an example.
Sozoro	Walking "sozoro" in the woods with no purpose is a fun.
Urara	The spring is now "urara" the best time. Probably people are in the mood of crying "URARA!!". "ura" young girl is in her best time of youth though the meaning of "ura" can not be found in the dictionary. "ura" young is "urawakai" in the dictionary.
Shittori	This cake is "shittori" with soft and comfortable wetness.

The sound of "silence"
    Did you hear the sound of "silence"? At a concert, appearing the conductor, soumeone "shush" and the audience are got shushed. In japan soumeone say "shii" and the audience become "shiin". The english "shush" and japanese "shii" are actually the same sound. In japan the silence is heard as "shiin".
    The snow fall makes no sound. But japanese says the strong snow fall, "snow is falling shin shin".
    If a man work keeping silence, he is working "mokumoku".
    If a petal of a flower falls silently, it falls "harari" at the instand of falling and then falls down dancing "hira hira".