Cardinal vowel 1, [i]

Produce a word beginning with a [j] sound: that is, something that begins with the letter in the spelling, such as ‘yes’. Hold the [j] sound. The sides of the tongue are pressed against the sides of the upper teeth, and the upper surface of the tongue is quite close to the hard palate. If you vigorously suck air in or out of the vocal tract, you should feel a cold, dry patch near the front part of the tongue and on the front part of the hard palate. Your lips should be spread, a little as though you are smiling. This articulatory posture is close to the posture of cardinal vowel 1, [i]. Now make your tongue a little tenser, and raise it a bit: you should generate friction by doing this, which sounds a bit like a -sound. The cardinal vowel is as extreme as a vocalic articulation can be while not producing friction, which is a consonant. So release some of the tension, and return to the frictionless sound.

This vowel is cardinal vowel 1 (CV1), [i]. It has a close (or high) and front tongue position; and it is made with spread lips. It is close to (but more extreme than) the sound spelt ‘ee’ in many varieties of English: for example, the word ‘bee’ in RP is close to this.