To talk about a place of articulation, we think of the space inside the mouth as having a front versus a back and a high versus a low area. Thus, in the pronunciation of heat and hit, we talk about "high, front" vowels because the sound is made with the front part of the tongue in a raised position In contrast, the vowel sound in hat is produced with the tongue in a lower position and the sound in hot can be described as a "low, back" vowel. The next time you're facing the bathroom mirror, try saying the words heat, hit, hat, hot. For the first two, your mouth will stay fairly closed, but for the last two, your tongue will move lower and cause your mouth to open wider. (The sounds of relaxation and pleasure typically contain lower vowels.) We can use a vowel chart, like Table 3.3 (based on Ladefoged and Johnson, 2011), to help classify the most common vowel sounds in English.