biāo​zhǔn​yīn

standard pitch

标准音 (標準音) biāo​zhǔn​yīn
standard pitch
A fixed musical frequency used as a reference for tuning instruments, such as A = 440 Hz.
standard pronunciation
The authoritative or accepted way of pronouncing a language, often based on a specific dialect.

Frequency

Written text
0.098 per million

Sources

Definitions
CC-CEDICT
Frequency data
BCC Corpus (BLCU)