"Sound that we can't hear--both ultrasonic, above our hearing range, and [infrasonic] below our hearing range--can damage hearing too," according to Dr. Michael Hoa, an ear surgeon at Georgetown ...

Enter ultrasonic and infrasonic sound. Ultrasonic sound, or ultrasound, is any sound above the 20,000 Hz threshold of human hearing. Dog whistles, plug-in pest control devices, and the ...

Human ear can perceive sound with in a frequency range of 20 Hz to 20 kHz. The sound frequency below 20 Hz is Infrasonic sound and above 20 kHz is Ultrasonic sound. Human ear is not sensitive to ...

The association of infrasonic waves in the atmosphere with auroral and magnetic activity is well recognized. Observations within the northern auroral zone suggest that the occurrence and the ...