euphony
standardizing
That is a trick question. You can't make a four letter word using all five vowels.
Some four-letter musical instruments that contain three vowels are "ukulele" and "oboe." While "ukulele" has more than four letters, "oboe" fits the criteria perfectly with three vowels and four letters. Other examples include "lute" and "horn," but they contain fewer vowels.
One of them is "iota."
The 8-letter word that contains four 'N's and the other four letters are all vowels is "announcer."
Some four letter words that have two vowels are:abetableacheacmeacneahemamenanteaveraxlebabebakebarebarebasebeadbeakbeambearbeatbeefbeenbeerbeetbidebikebiteblueboarboatboilbonebookbootboreboutbozobriecafecagecakecamecanecapecarecasecavecluecodecoedcoilcoincolacomacomeconecopecorecovecubecurecutedaledamedaredatadatedaubdazedeaddeafdealdeardeeddeemdeepdeerdelidemodialdicedimedinediredivadivedoledomedonedopedovedozedudedukedunedupeeachearlearneastechoecruedenedgeeditelseemiremitepicergoeveneverevilewerexamexitfacefadefailfairfakefamefarefatefaunfauxfazefearfeatfeedfeelfeetfetafetefeudfieffifefilefinefirefivefleafleefluefoalfoamfoilfootforefreefumefusegagagaingaitgalagalegamegapegategavegazegeargeargenegivegleegluegoadgoalgoalgoatgoesgonegoodgoofgoopgoregoutguruhailhairhalehaloharehatehaulhavehazeheadhealheaphearheatheedheelheirhereherohidehikehirehivehoaxhoboholehomehonehoodhoofhookhoophoothopehosehourhugehulaibexibisiconidleidolintoirisironisleitemjadejailjavajeerjivejoinjokejudojutekalekeelkeenkeepkenokilokitekiwikneekookkudolacelaidlainlairlakelamelanelatelaudlavalazeleadleafleakleanleapleekliarliceliedlienlifelikelimelimolinelionliveloadloafloamloanlobelocolodelogoloinlonelookloomloonlooplootlopeloreloseloudloutlovelubelugelureluteluxemacemademagimaidmailmaimmainmakemalemamamanemarematemaulmazemeadmealmeanmeatmeekmeetmemomenumeowmeremesametemicamicemikemilemimeminemiremitemoanmoatmodemoilmojomolemoodmoonmoormootmopemoremotemovemulemumumusemutenailnamenapenearneatneedneonniceninenodenoelnonenooknoonnopenosenotenounnovanudeoathodorogleogreoinkokraomenomitonceontooopsopalopenoralorcaorzoovaloveroxenpacepagepaidpailpainpairpalepanepapaparepatepavepeakpealpearpeatpeekpeelpeeppeerpeonpesopicapierpikepilepinepipepitapleapoempoetpokepoleponepopeporeposepucepukepumapurequadquayquidquipquitquizracerageraidrailrainrakeraperarerateraverazereadrealreamreaprearredoreedreefreekreelreinricerideriferilerimeriotriperiseriteroadroamroanroarroberoderoleroofrookroomrootroperoseroteroutroveruberuderuinrulerusesafesagasagesaidsailsakesalesamesanesarisavesealseamsearseatseedseekseemseenseepseershoesidesilosinesiresitesizesoaksoapsoarsodasofasoilsolesolosomesoonsootsoresoulsoupsourspuesuetsuitsuretabutacotailtaketaletametapetaretarotaxiteaktealteamtearteatteemteentheethoutidetiertiletimetinetiretoadtofutogatoiltometonetooktooltoottoretotetourtreetriotruetubatubetunatunetutuulnaundounituntouponurgeuservainvalevanevasevealveerveilveinvetovialviceviewvilevinevisavisevoidvolevotewadewadiwagewaifwailwaitwakewanewarewaveweakwealweanwearweedweekweepwerewheewhoawidewifewilewinewipewirewisewokewoodwoofwoolworewoveyeahyearyetiyogayokeyoreyouryulezealzerozetazitizonezoom
An eight letter word with three vowels using those letters is scavenge.Eight letter words with four vowels using those letters are agencies and envisage.
21^4
queue
isle,else,also,
queue
The seven U.S. states with more than four vowels in their names are: California, Colorado, Louisiana, Minnesota, Mississippi, Pennsylvania, and South Carolina. Each of these state names contains a combination of vowels that exceeds four.