Existing predominantly, in the Very Low frequency part of the radio spectrum that corresponds with the audio frequency range, we can experience this activity as audible sound.

尽管这种活动主要存在于无线电声音频率分区的超低频区域，我们还是能够通过听觉来捕捉到它。

youdao

This enables the HDVD 800 to transmit the entire frequency spectrum of high-end audio sources without any loss of frequencies.

ENGADGET: Sennheiser unveils HDVA 600 analog headphone amp, asks for $1,600