You are being pro­vid­ed with a book chap­ter by chap­ter. I will request you to read the book for me after each chap­ter. After read­ing the chap­ter, 1. short­en the chap­ter to no less than 300 words and no more than 400 words. 2. Do not change the name, address, or any impor­tant nouns in the chap­ter. 3. Do not trans­late the orig­i­nal lan­guage. 4. Keep the same style as the orig­i­nal chap­ter, keep it con­sis­tent through­out the chap­ter. Your reply must com­ply with all four require­ments, or it’s invalid.
I will pro­vide the chap­ter now.

KEEP IT DOWN!
 
 
�            The sound of the Big Bang hap­pened on such a low fre­quen­cy that
even if humans were around, they wouldn’t have been able to actu­al­ly
hear it!
 
�            Synes­the­sia is a con­di­tion where peo­ple see dif­fer­ent col­ors
accom­pa­ny­ing music and oth­er sounds. It’s esti­mat­ed that 1% to 4%
of the pop­u­la­tion has synes­the­sia.
 
�            Mod­ern sci­en­tists believe the vol­canic erup­tion on Mount Thera,
Greece around 1,600 BCE mea­sured sev­en on the Vol­canic
Explo­siv­i­ty Index (VEI). If so, it was the loud­est sound in his­to­ry.
 
�       Cats and dogs have an excel­lent sense of sound, but they’re noth­ing
com­pared to dol­phins. Dol­phins can hear sounds 15 miles away.
 
�            A whip needs to trav­el faster than the speed of sound to make the
crack­ing noise. That means a whip goes 767 miles per hour when it’s
cracked.
 
�            Hear­ing loss is a glob­al prob­lem. Accord­ing to the Hear­ing Health
Foun­da­tion, the num­ber of peo­ple with hear­ing loss is more than
those with Parkinson’s Dis­ease, Epilep­sy, Alzheimer’s Dis­ease, and
Dia­betes com­bined.
 
�            Pale­on­tol­o­gists aren’t sure of the exact sounds dinosaurs made, but
they prob­a­bly includ­ed snorts, grunts, hiss­es, and roars, depend­ing
upon the species. The Lam­beosaurus may have even made a honk­ing
noise due to the hol­low crest on its head.
 
�            Mol­e­cules are need­ed to pro­duce sound and since there are no
mol­e­cules in space, there’s no sound in space. It kind of ruins the fun
of Star Wars and Star Trek!
 
�            The loud­ness of sound is mea­sured in deci­bels. A typ­i­cal car horn
puts out 100–110 deci­bels, while a cry­ing baby can belt out 115
deci­bels!
 
�       The first sound film, or “talkie” as they were called at the time, was
The Jazz Singer in 1927. Silent films con­tin­ued to be pro­duced into
the 1930s.
 
�       The Orfield Labs ane­choic cham­ber in Min­neapo­lis, Min­neso­ta was
list­ed as the “qui­etest place on Earth” in 2005 and 2013 by the
Guin­ness Book of World Records.
 
�            The Alpheus or pis­tol shrimp is only about two inch­es long when
ful­ly grown, but it’s snap­ping claws can cre­ate 218 deci­bels of sound.
That’s right up there with whales!
 
�       The Last Ice Age would have been very audi­ble to those liv­ing near
the glac­i­ers. Just as they do today, the glac­i­ers would have been
notable for their crack­ling, gur­gling, and boom­ing nois­es.
 
�       The atom­ic bombs dropped on the Japan­ese cities of Hiroshi­ma and
Nagasa­ki on August 6 and 9, 1945, respec­tive­ly, reached 240
deci­bels.
 
�       Infra­sound is sound waves that reg­is­ter below what humans can hear.
Hom­ing pigeons can per­ceive infra­sound, but how they use that for
nav­i­ga­tion is a mys­tery.
 
�            A “hum­ming” sound of unknown ori­gin has plagued Taos, New
Mex­i­co for decades. Strange­ly, though, only 2% of the pop­u­la­tion can
appar­ent­ly hear this noise.
 
�            The world’s first musi­cal instru­ments were heard in Mesopotamia
and Egypt in about 2,800 BCE. Some of the ear­ly instru­ments
includ­ed lyres, sis­tra, and cym­bals.
 
�       Tin­ni­tus is an annoy­ing ring­ing in the ears. Accord­ing to the NIDCD
Epi­demi­ol­o­gy and Sta­tis­tics Pro­gram, 10% of Amer­i­cans have
expe­ri­enced it in the last year.
 
�            Hertz (Hz) is the mea­sure of vibra­tions or sound waves per sec­ond.
The range for humans to hear some­thing is between 1,000 and 6,000
Hz.
 
�            In the 500s BCE, the Greek colony, Sybaris, in Italy, passed one of
the ear­li­est known noise ordi­nances. It pro­hib­it­ed tin­smiths and
roost­ers from the city lim­its.
 
�            The ossi­cles is the col­lec­tive name of the three bones in the mid­dle
ear: ham­mer, anvil, and stir­rup. They are the three small­est bones in
the human body, but with­out them, we’d be deaf.
 
�            A mas­sive earth­quake hit the Greek island of Rhodes in 226 BCE
that could be heard for miles. It was big enough to destroy a large