I understand this, however I have two questions. What does fistikci sahap (with the right letters) mean? (just curious) and in what way are these consonants 'unvoiced'?
The consonants in "fıstıkçı şahap" are the same consonants in the list of unvoiced consonants.
Most consonants have a voiced and an unvoiced version. This refers to whether you engage your vocal cords or not in making the sound. You can feel the difference if you touch your adam's apple while you're saying them. For instance, when you say "dad" you should feel your throat vibrate for the whole word (d is a voiced consonant and vowels always use vocal cords). If you say "tot" on the other hand, you should notice that your throat only vibrates during the time you're saying the vowel. "t" is an unvoiced consonant but is otherwise pronounced with just about the same mouth shape as "d"