How Do Frequencies Affect Pitch?

Still sticking to World Book Student, I discovered how frequencies affect pitch. I found the answer here. In summary, a frequency is how frequent sound waves pass a certain point in a second. Pitch is determined by frequency and is how high or low we hear the sound to be. Frequencies are measured in hertz. The average human can hear up to 20,000 hertz. Regarding how frequencies affect pitch, the higher the frequency, the higher the pitch. In contrast, a lower frequency makes a lower pitch. Once again, thanks to World Book, and for work cited please reference "How Are Sound Waves Created?".