Sound cannot travel in space because sound cannot travel through _______.

154Hz sound frequency comes under ________ .

• Sounds with frequencies less than 20Hz are called infrasound.
• Sounds with frequencies more than 20kHz are called ultrasounds.

Infrasound have more ____________.

ECG uses _________ for the medication.

Human cannot listen to _________.

Kidney stones can be cured using ________.

• High energy sound waves are passed through the body without injuring it and break the stone into small pieces.
• This technique is known as lithotripsy.

A hearing aid ____ the sound before directing it into the ears of the person wearing it.

Giraffe uses ______ sounds for communication.

Which of the following parts of the ear transmits the electrical signals to the brain for interpretation?

• The optic nerves relay messages from your eyes to your brain to create visual images.
• Cochlea is the part of inner ear.
• Blood vessels deliver blood to the organs and tissues in your body.

Increase in wavelength ___________ frequency.

• Wave speed= frequency × wavelength.
• Frequency = wave speed/wavelength.

The frequency of vibration of an object is 25000 Hz. A person ____ hear it.

Frequency above 20KHz is called ultrasound.

Which of the following is not a part of the middle ear?

The frequency of vibration of an object is 150 Hz. A person ____ hear it.

The frequency of the sound can be modified to change the infrasound to _____.

When an ear drum encounters a rarefaction, it ____.

Compression or high pressure push the eardrum inwards.

When the air pressure near the ear drum increases, it ____.

Low pressure regions or rarefactions pull the eardrum outwards.