What is the main reason high frequency consonants can be easier to lip-read than vowels?

High frequency consonants are often easier to lip-read than vowels primarily due to their visual distinctiveness. When considering the features of speech that are visible on the lips, high frequency consonants such as /s/, /f/, and /t/ typically have more noticeable articulatory movements. These consonants require specific lip and tongue positions that can be clearly observed by a viewer.

In contrast, vowels tend to involve more open mouth positions, which can create less visually distinctive cues. The differentiation among vowels may not convey as much visual information since they often share similar mouth configurations and are produced with less precise movements compared to many consonants. Consequently, individuals reliant on lip-reading can more easily identify consonants due to the sharper visual signals they provide.

The other choices present viable statements about speech and language, but they do not accurately capture the core reason why consonants are easier to lip-read. For example, while volume does have an impact on audibility, it does not influence the visual comprehensibility of speech. Similarly, while vowels play a significant role in the phonetic structure and meaning of words, their visual representation is less distinct compared to consonants. Lastly, the age at which consonants are learned is not a direct factor affecting the