Answer:
the result of each human voice having a distinctive timbre
Explanation:
Each individual has a voice as unique as their finger prints, this is the reason you can tell the voices of people apart. Assuming every human sounds the same, it would be difficult to differentiate callers on phones. The distinct timbre of the human voice is as a result of the complex processes by which voices are produced, the activity of the lungs, voice box, larynx in voice production.
*were presidents; George Washington was the first president; Barack Obama was the first African American president.
