how different are ear and eat?

Hi

I want to know the sound different of "i" from ear, eat.

these are phonetic symbols.

[ɪr] or [íər] (I think first one is okay but second one has a high pitch.)

[i:t] (this one also has a high pitch)

Pitch is not really relevant.

/i:t/ is a single vowel;
/ɪər/, /ɪə/ in most BrE dialects, is a diphthong, a glide from /ɪ/ to /ə/.

Note that the first sound in /ɪə(r)/ is the short /ɪ/, not the long /i:/

Eat is one long vowel followed by /t/
Ear is two short vowels. (Most of us don't say the 'r'.)

Pre-r environment is a special beast: tense vowels become laxer. The natural pitch of /i/ vowel is higher than that of /ɪ/. In the word 'ear', you hear the latter vowel.