20,000 Hz is considered to be a high-pitched sound. The human ear can typically hear sounds between 20 Hz and 20,000 Hz, with the range of human hearing varying from person to person. Sounds above 20,000 Hz are considered to be ultrasonic and cannot be heard by humans.

The loudness of a sound is determined by its amplitude, or the strength of the sound waves. A sound with a high amplitude is considered to be loud, while a sound with a low amplitude is considered to be quiet. The unit of measurement for sound intensity is the decibel (dB). A sound of 0 dB is considered to be the threshold of human hearing, while a sound of 120 dB is considered to be the threshold of pain.

So, a sound of 20,000 Hz can be considered to be both high-pitched and loud, depending on its amplitude.