How do you pronounce the "ơ" letter in Vietnamese?

The "ơ" letter in Vietnamese is an unrounded, mid-central vowel, similar to the English schwa sound "ə" found in words like "sofa" or "comma". However, the "ơ" sound in Vietnamese is a bit more tense and held slightly longer than the English schwa. In the International Phonetic Alphabet (IPA), this sound is represented as /ɤ/.