Keep it down! Sound is every­where, yet some of the most remark­able nois­es through­out his­to­ry go unno­ticed by the human ear. For instance, the sound of the Big Bang, though it marked the birth of the uni­verse, was too low in fre­quen­cy for humans to hear. This phe­nom­e­non high­lights the lim­i­ta­tions of human hear­ing, espe­cial­ly when com­pared to the vast­ness of sound fre­quen­cies present in nature. Inter­est­ing­ly, synesthesia—a rare con­di­tion affect­ing about 1% to 4% of people—blurs the bound­aries between the sens­es. Those with synes­the­sia may see col­ors when they hear sounds, a fas­ci­nat­ing twist that com­bines audi­to­ry and visu­al expe­ri­ences, show­ing how diverse human per­cep­tion can be. It serves as a reminder of the com­plex­i­ty of sound and how dif­fer­ent indi­vid­u­als expe­ri­ence it.

Over time, human and ani­mal hear­ing abil­i­ties have been sub­jects of fas­ci­na­tion. Cats and dogs are known for their supe­ri­or hear­ing com­pared to humans, but dol­phins far sur­pass them. These marine mam­mals can detect sounds up to 15 miles away, giv­ing them a remark­able advan­tage when nav­i­gat­ing the vast ocean. The whip, too, is an exam­ple of the speed and pow­er of sound—its crack occurs when the tip trav­els faster than the speed of sound, reach­ing speeds of 767 miles per hour. Such exam­ples remind us of the incred­i­ble ways sound oper­ates in the ani­mal king­dom. On the oth­er hand, human hear­ing, while less advanced, remains a sig­nif­i­cant aspect of dai­ly life. Yet, hear­ing loss con­tin­ues to be a glob­al issue, affect­ing more peo­ple than Parkinson’s Dis­ease, Epilep­sy, Alzheimer’s Dis­ease, and Dia­betes com­bined. The mag­ni­tude of this health con­cern shows the impor­tance of sound in our lives and the need to pro­tect our hear­ing.

The his­to­ry of sound and its role in cul­ture and tech­nol­o­gy is rich and var­ied. For exam­ple, while the sound of the glac­i­ers dur­ing the Last Ice Age would have been a con­stant reminder of the planet’s chang­ing cli­mate, today, the con­cept of sound has evolved into some­thing more sci­en­tif­ic. Space, for instance, remains eeri­ly silent because there are no mol­e­cules in the vac­u­um to trans­mit sound. This is why space scenes in movies like Star Wars and Star Trek are devoid of real­is­tic sound. Mean­while, on Earth, the loud­est sounds ever record­ed, like the atom­ic bombs dropped on Hiroshi­ma and Nagasa­ki, reached an unimag­in­able 240 deci­bels, a lev­el that far exceeds the thresh­old of pain for the human ear. The cre­ation of sound is not always linked to human activ­i­ties; even tiny crea­tures like the pis­tol shrimp, which can gen­er­ate a sound of 218 deci­bels with its snap­ping claws, remind us how sound in nature can sur­pass even the loud­est human-made nois­es.

Sound plays a sig­nif­i­cant role in both the nat­ur­al world and human life, with a range of fre­quen­cies from infra­sound to the high­est pitched tones. Infra­sound, which is below the range of human hear­ing, is used by cer­tain ani­mals, such as pigeons, for nav­i­ga­tion. Although how they use these sound waves remains a mys­tery, the fact that ani­mals per­ceive sounds beyond our com­pre­hen­sion empha­sizes the depth of the nat­ur­al world. Sim­i­lar­ly, sounds that humans can hear, like the strange hum­ming noise that has plagued Taos, New Mex­i­co for decades, high­light the enig­mat­ic qual­i­ties of sound. This hum, which only a small per­cent­age of the pop­u­la­tion can hear, is just one exam­ple of how sound can have both sci­en­tif­ic and mys­te­ri­ous qual­i­ties. The desire to under­stand such phe­nom­e­na, whether through physics, biol­o­gy, or cul­tur­al his­to­ry, under­scores the impor­tance of sound in shap­ing our envi­ron­ment.

The impact of sound on human cul­ture is also pro­found. The ear­li­est musi­cal instru­ments, like lyres and cym­bals, were used in ancient Mesopotamia and Egypt around 2800 BCE. These instru­ments not only cre­at­ed music but also shaped the cul­tur­al iden­ti­ty of ear­ly soci­eties, show­ing the time­less nature of sound as a form of expres­sion. Addi­tion­al­ly, the study of sound has allowed us to devel­op tech­nolo­gies such as hear­ing aids and cochlear implants, help­ing peo­ple with hear­ing impair­ments expe­ri­ence sound again. With the glob­al increase in cas­es of tinnitus—an inces­sant ring­ing in the ears that affects 10% of Amer­i­cans in the past year—it’s clear that sound plays a crit­i­cal role in both the health and well-being of indi­vid­u­als. The abil­i­ty to hear is so vital that even the small­est bones in the human body, the ossi­cles in the mid­dle ear, are essen­tial for trans­mit­ting sound to the brain.

Final­ly, noise ordi­nances, dat­ing back to the 500s BCE in the Greek colony of Sybaris, show that the reg­u­la­tion of sound has been impor­tant for thou­sands of years. The ancient law pro­hib­it­ed noisy activ­i­ties, such as the clang­ing of tin­smiths and the crow­ing of roost­ers, to pre­serve the peace. Mod­ern noise reg­u­la­tions con­tin­ue to play a cru­cial role in main­tain­ing pub­lic health, ensur­ing that cities remain liv­able despite the hus­tle and bus­tle of dai­ly life. The impor­tance of sound reg­u­la­tion is fur­ther demon­strat­ed by places like the Orfield Labs ane­choic cham­ber in Min­neapo­lis, con­sid­ered the qui­etest place on Earth. In a world where sound is both a tool and a chal­lenge, under­stand­ing its effects and man­ag­ing its impact is essen­tial for a bal­anced, healthy soci­ety.