In early English literature we have
“They herde no pype, ne flagel” also “And a pypyd a moot in a flagel” about AD 1300 in “Sir Gawain and the Green Knight” The flagel being an early whistle.
Chaucer uses ‘flowte’ and ‘pipe’
“They haueth in greet mangerie
Harpe, tabor, and pype for mynstralcie.” 1387
“Calam hath that name of thys worde Calando. sownyng: and is the generall name of pypes, A pype hyghte Fistula; for voyce comyth therof For voyce hyghte Fest in grewe, other sowne.” 1398 Here we have pipe again and fistula which is also a word for whistle that is often used for whistle in early modern English.
“Sambuca is the Ellerne tree bro tyll. And the bowes therof ben holowe and voyde and smothe. And of those same bowes ben pipes made and also some manner symphony.” AD1398 Here we have whistle made from elder tree branches being called pipes.
“When they hadde these instrumentes they recorded songes besyly tylle that they were . . . parfyte ynowe in al maner musike.” AD 1483 John Lydgate here uses the word ‘recorded’ in the the old sense of ‘sing like a bird’ which is one of the theories of the origin of the name recorder.
“Therfore first recorde thou, as birde within a cage,
. . . thy tunes tempring longe,
And then . . . forth with thy pleasaunt songe.” AD 1510 Alexander Barcley in “Mirror of good manners” Again use of the word recorde to mean to whistle or flute a song like a bird.
“I recorde as yonnge byrdes do: Je patelle.” 1530
“This byrde recordeth all redy, she wyll synge within a whyle: C’est oyeslet patelle desja, elle chantera avant quil soyt longemps.” 1530
Recorder a pype fleute a ix neufte trous. 1530
“… and thinke it not a smalle thinge to have lerned to playe on the pype or the recorder.” 1532 Pipe and recorder are different here.
There are thousands of references to flutes which seem to refer to whistles and sometimes to recorders.
There are extant whistles in Britain from about AD 900 made with bone and used clay fipples. They were diatonic and possibly not a lot different to the ones the writings above refer to. It was a few hundred years later that we have the first find of a Viking whistle in Dublin but that was similar to the earlier ones found in Britain which I think shows that the same instrument was quite widespread.
Sorry, this turned into a mess. I was trying to give a few references to early names used for whistles in English literature. 