Here are the rules as taught in Greek schools
Some words sometimes retain the final v or lose the final v.
The final ν is only retained in feminine articles/pronouns before vowels and the following consonants / combinations: π, κ, τ, ψ, ξ, μπ, ντ, γκ, τσ, τζ.
-the article την
-the personal pronoun third person αυτήν, την
-the particles δεν and μην
These words retain the final ν when the word that follows begins with a vowel or with the consonants κ, π, τ, the double consonants μπ, ντ, γκ, ξ, and ψ.
For example "την είδα", "I saw her", "την κοπέλα", "the girl", "την ντουλάπα", "the cupboard", "δεν ξέρω", "I don’t know".
Therefore, these words lose the final ν when the following words begin with one of the other consonants: β, δ, γ, φ, θ, χ, μ, ν, λ, ρ, σ, ζ.
For example: "τη δασκάλα", "the teacher" (feminine), "τη θυμήθηκα", "I remember her", "δε θέλω". "I don’t want"
In written form, the final ν is always kept on the masculine singular definite and indefinite articles (τον the, έναν a/an one)
For example: "τον νέο άντρα" "the young man" when used for the masculine word “man” but "το νέο είδηση" "the new message".
The final n is always used for the article των, the personal pronoun αυτόν, τον, and σαν
For example: "των θαλασσών", "the seas", "αυτόν θέλει", "he wants", "τον φώναξε","I called him", "σαν λύκος", "like a wolf",
Personally, I don't hear anything wrong with the pronunciation of Ελληνικά. Of course, it doesn't sound 100% natural, as the audio is not the voice of a native, but a TTS (text-to-speech) program. But it's decent. I do understand that the concept of the accent might be a bit hard to grasp for English speakers, but Greek is not as "flat" as English is when it comes to pronunciation, which is why some learners misplace the accents on vowels. It's something you'll get used to, with time and practice. ^.^
Thanks for trying to help. However, my "first" language HAS an accent mark...that's the reason I ask :) In Spanish, it's the very same accent shown in these couple of examples, too...but perhaps it doesn't apply EXACTLY the same way? If it were in Spanish, the accent mark would be EXACTLY over the vowel (in the exact syllable) which is stressed in speech, not over the next or second over backwards...that's what I heard in both examples: They accent mark was placed in a DIFFERENT syllable than the one they stressed in the audio!
I agree with Dimitra, the audio, while not amazing, sounds in fact accurate to a native's ears.
The accent in Greek works in the same way it does in Spanish: you stress the vowel on top of which the accent is placed.
Please try these recordings; do they sound better? They are all very clear but the rhythm / intonations varies a lot. The stress placement however cannot be questioned: it is correct.