Which of the following words has an initial consonant sound that is voiceless? A) Zebra B) Giraffe C) Joke D) Cheese

A voiceless sound is a speech sound produced without vibration of the vocal cords. You can test this by placing your hand on your throat while making the sound. If you feel no vibration, it's voiceless.

• A) Zebra: The initial sound is /z/. This is a voiced sound (vocal cords vibrate).
• B) Giraffe: The initial sound is /dʒ/ (like the 'j' in 'jump'). This is a voiced sound.
• C) Joke: The initial sound is /dʒ/. This is a voiced sound.
• D) Cheese: The initial sound is /tʃ/ (like the 'ch' in 'church'). This is a voiceless sound (vocal cords do not vibrate).

The word "Cheese" has an initial consonant sound /tʃ/ which is voiceless.

The final answer is $\boxed{\text{D) Cheese}}$.