Question

keywords:
1. sound
2. Frequency​

Answer 1

Explanation:

Frequency, sometimes referred to as pitch, is the number of times per second that a sound pressure wave repeats itself. ... The units of frequency are called hertz (Hz). Humans with normal hearing can hear sounds between 20 Hz and 20,000 Hz. Frequencies above 20,000 Hz are known as ultrasound

Answer 2

Answer:

Frequency, sometimes referred to as pitch, is the number of times per second that a sound pressure wave repeats itself. ... The units of frequency are called hertz (Hz). Humans with normal hearing can hear sounds between 20 Hz and 20,000 Hz. Frequencies above 20,000 Hz are known as ultrasound