Human ear perceives frequencies between 20 Hz (lowest pitch) to 20 kHz (highest pitch). All sounds below 20 Hz are qualified as infrasounds, althought some animals (ex. mole-rat, or elephant) are hearing them. Similarly, all sounds above 20 kHz are qualified as ultrasounds, but their are sounds for a cat or a dog (up to 40 kHz) or for a dolphin or a bat (up to 160 kHz).
Do not confuse bit rate transfer and frequency range of what is being transferred.