Only the last phoneme in -ый
is similar to ey
in hey
, but not the entire syllable.
I'm not entirely clear what part of the syllable is a problem.
The divergence may be due to difference in expression of different speakers, without proper effort in articulation (like in fluent speech) it may sound as just -ы
without -й
, which at this position is very short anyway (not without a reason the letter is named "short И"), getting reduced because the word stress is far removed from it.
I didn't notice it being pronounced as -ий
in the clips.
The word contains both vowels сИльнЫй and in the Wiktionary clip difference in their pronunciation is apparent. И
softens consonants which precede it (save for Ц/Ж/Ш
, which in combination ЦИ/ЖИ/ШИ
are pronounced as ЦЫ/ЖЫ/ШЫ
) whereas in the clip Н
before -ый
isn't softened, which would be the case had the ending been pronounced as -ий
.
If you're trying to understand how ы
is to be properly pronounced, i'd suggest taking notice of how English duh
interjection is pronounced, because its vowel is quite close.