Radio Waves vs Sound Waves – Completely Different, Right?


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Rafeal Hart


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Norris Howe

Radio Waves vs Sound Waves

You might get confused with radio and sound waves because people associate ‘radio waves’ with their home’s ‘radio.’ Radio waves vs sound waves: what exactly sets them apart?

For your information, the main difference is that sound waves require a medium to pass through, while radio waves don’t. Yes, radio waves are used to tune into your radio. But to produce sounds, you’ll need sound waves transmitted using a medium, which is your radio.

Here’s an overview of the difference between radio waves vs sound waves GCSE students can easily understand:


Radio Waves

Sound Waves

Wave Type

Electromagnetic wave

Mechanical wave

Medium Requirement



How It Occurs

Charged particles

Mechanical vibrations

What It Produces

Energy and visibility

Energy and sounds


186,000 miles per second

0.212778 miles per second

What Are Radio Waves?


Radio waves are electromagnetic waves that are generally used for communication purposes. This is the basic building block of radio communication, where radio waves are absorbed by radio to tune into radio frequencies. But you’ll need mechanical vibrations from sound waves to hear the radio stations.

Radio waves travel through the Earth’s atmosphere and are the longest waves in the electromagnetic spectrum (ES).

Because radio waves are at the end of the ES, they have the lowest frequencies among other waves. This means radio waves have lower energy levels than their counterparts, such as ultraviolet rays, X-rays, and gamma rays.

1. Properties Of Radio Waves

Here are some facts about radio waves and their characteristics:

  • Speed of light

If you’re wondering ‘how fast do radio waves travel?’ or ‘radio waves travel at what speed,’ they travel at the speed of light. That’s around 186,262 miles per second.

  • Movement and feel

Radio waves cannot be seen with the naked eye. They also can’t be touched or felt but can pass through objects.

  • Frequency

Radio waves have short frequencies. This ranges from 3 to 1,000,000,000 Hz.

  • Occurrence

Radio waves occur naturally from objects with magnetic fields. Because it has magnetic and electronic properties, these waves reflect, refract, and diffract. Radio waves can also polarize.

2. Uses And Applications Of Radio Waves


Radio waves can be divided into bands. And depending on which band it belongs to, its application changes. Here are some of the most common uses of radio waves:

  • AM, aviation, and marine radios

These use very low frequencies (less than 3 Mhz) to receive communication. These can be comparable to the energy of lightning.

  • Cellphones, television, GPS, and FM radios

Radio waves of higher frequencies (3 Mhz to 3 Ghz) are much stronger than those of low bandwidth. These appliances produce more signal and have clearer reception.

  • Radio telescopes

Radio waves with extremely high frequencies (above 3 Ghz) can detect and produce images to see celestial bodies, such as planets, stars, etc. Sometimes, these overlap with microwaves, which are next in the electromagnetic spectrum.

What Are Sound Waves?


Is sound an electromagnetic wave like radio waves? No. Sound waves are mechanical waves caused by vibrations. To produce sound, you’ll need a medium. The medium could be air, water, or any solid substance.

When sound waves are present in these mediums and are disrupted, the waves will move in the same direction as the medium (longitudinal waves) and make a sound.

1. Properties Of Sound Waves


Sounds can be altered depending on a lot of factors. Here are some characteristics of sound waves that make each sound we hear unique:

  • Speed of sound

On average, the speed of sound is 0.212778 miles per second. However, different weather conditions could affect this. In fact, sound travels slower in colder temperatures.

Aside from that, the speed of sound is also slower in the air compared to solids and liquids. The faster the sound speed is, the less sound lag time you’ll hear.

  • Frequency

Frequency affects the sound’s pitch. The lower the sound frequency is, the lower the pitch of the produced sound.

For example, 25 Hz would sound very low, deep, and rumbling. Sounds at 18,000 Hz, on the other hand, would be very squeaky and high-pitched.

  • Amplitude

The sound’s volume depends on the sound wave’s amplitude. If the sound has a high amplitude– it will also have a loud sound. This is measured through decibels (dB).

2. Uses And Applications Of Sound Waves

Sound waves have many purposes– not just for us humans to hear. Here are some of the most common uses of sound waves.

  • Hearing

Sound waves let us hear sounds ranging from 20 to 20,0000 Hz. Anything higher than that is so high-pitched that it can’t be heard anymore.

  • Echoes


Sound echoes can help with animals’ search for prey. This is vital for animals like bats living in the dark. The hunting process using echoes is called echolocation.

  • Medical purposes


Sound waves higher than 20,000 Hz are called ultrasonic waves. These waves can be used for medical equipment– such as surgical tools, sonograms (ultrasound imaging), and sonar systems.

  • Sound navigation ranging (SoNaR)

Sound waves can be used to track and navigate marine transportation and aircraft. This can be done by sending sound pulses and receiving the reflected sounds.

Sound Waves vs Radio Waves: Similarities

Sound and radio waves are very different from each other. In fact, the only similarity they share is that both are ‘waves.’ All waves transmit energy and can reflect, diffract, refract, and interfere with other substances. They also have a defined speed, amplitude, frequency, and wavelength.

Differences Between Sound And Radio Waves


Radio and sound waves are used for different things. But they co-exist and are invisible things that we encounter in our daily lives.

  • Nature and reception

A radio wave is electromagnetic radiation, whereas a sound wave is a mechanical vibration. Radio waves don’t need a medium for receiving, while sound waves need one.

  • Transmission

Radio waves are transmitted through signal-detecting devices such as antennas. Sound waves can be transformed into sound through vibrations or impulses.

  • Frequency

Radios have higher frequencies, from 3 kHz to 300 GHz. Sound waves have frequencies ranging from 20 Hz to 120 kHz.

Frequently Asked Questions


How are sound waves used in medicine?

Sound waves are used in medicine through ultrasonic sound waves. These sound waves are used in medical equipment, such as ultrasound imaging tools, sonar systems, and surgical equipment.

How are radio waves used in satellite communication?

Satellites in outer space use radio waves to send signals to Earth. They can relay their location and important scientific data obtained by the satellite through antennas.

What is the relationship between radio waves and sound waves?

Radio and sound waves go hand-in-hand when listening to the radio. For radio to work, it must receive signals (radio waves) from an antenna. Once it has a clear signal, mechanical vibrations shall be produced for sound waves to convert these into sound.


Radio waves vs sound waves: what’s the difference? Comparing these two is like differentiating an apple and an orange– they are drastically different from each other.

They are different in nature, frequency, and speed and have distinct reception and transmission methods. More than that, they have different purposes.

Radio and sound waves are equally important; without these, we might not be able to see and hear clearly– life on Earth would be very different.

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