How Do Wireless Bluetooth Earbuds Work?

How Do Wireless Bluetooth Earbuds Work?

Today’s generation has seen rapid growth in technology. Our daily lives are filled with electronic gadgets and we practically live on Internet!

This rapid advancement in technology that we’ve witnessed in the last 20 years has made it possible to make our lives a little bit happier by enabling us to listen to our favorite music whenever we want with the help of “small ear-speakers”.

These little “ear-speakers” have gone through different stages of development. It all started as a big pair of portable headphones which sized down to these tiny ones we now know as Earbuds.

With further development, Earbuds became truly wireless and made our lives a lot easier. This wire-free life that we enjoy is enabled by Bluetooth Technology. Of course, we all know that.

But have you ever wondered how this technology works? How do Wireless Bluetooth Earbuds work? That’s what we’re gonna delve into!

But first, what is Bluetooth?

Bluetooth technology is a short-distance radio wave system. The newest technology allows you 240m of range (you can be as far as 800 feet away from the source and Bluetooth will still be able to transmit the waves). The traditional ones had a smaller range of only about 50m (165 feet).

How Do Wireless Bluetooth Earbuds Work?

To know the mechanism of Bluetooth Earbuds, let us first discuss:

What are Bluetooth Earbuds?

Bluetooth Earbuds are wireless devices that receive the audio signal from the source through Bluetooth transmission instead of wires.

For such Earbuds to function, they require certain components:

  • Bluetooth Receiver
  • Radio Frequency (RF) Antenna
  • Computer Chip
  • Speaker Drivers (as seen in all kinds of headphones)

How do they work?

Wireless Earbuds transmit audio signals using low-powered radio signals.

There are two components that play a major role in wireless Earbuds: Transmitter and Receiver.

A transmitter is found in the audio source (smartphones, etc.) in the form of a small chip with Bluetooth radio software. The transmitter transmits audio in the form of a carrier wave to the receiver.

The carrier wave is a sine wave in the frequency range of 900 MHz up to 3.2GHz.

The receiver, as mentioned above, is included in the earbuds. It picks up the carrier waves and decodes the audio signal.

NOTE: Wireless transmission takes place at the same frequency as the transmitter and the receiver.

Analog Audio and Digital Audio Transmission

There are two kinds of audio that are transmitted wirelessly- analog audio signal and digital audio signal.

Source: meractsan

Analog Audio Transmission– The Analog Audio Signal Transmission is done through Frequency Modulation (same as FM Radio).

Source: slideserve

The transmitter modulates the single-frequency carrier wave which is accepted by the receiver. The receiver then will demodulate the carrier wave to keep the frequency variation as low and concise as possible. It does not use Bluetooth technology.

This type of FM transmission can be used to carry stereo sound.

Digital Audio Transmission– Bluetooth Earbuds mostly receive digital audio.

With the growth in digital technology, many headphones can now receive digital audio wirelessly. Bluetooth is the standard for transmitting Digital audio through a method called pulse-key shifting (PSK).

Digital Audio is basically the digital representation of Analog Audio.

source: applidium

Through the PSK method, the single-frequency carrier wave is modulated by changing the sine and cosine inputs at the same time. The receiver accepts the modulated frequency wave and demodulates it to decode the audio.

Most Bluetooth Headphones have PSK modulation (Digital Audio Transmission) that works in the Radio Frequency Range of 2.400GHz – 2.4835 GHz

Radio Frequency refers to the radio waves or electromagnetic waves that travel through a medium like air.

Bluetooth Earbuds also have a small computer chip incorporated that enables them to connect and communicate with other devices like TV, Radio, etc.

Battery Operated Bluetooth Earbuds

Bluetooth Earbuds are battery-powered. Based on this, they can be divided into Class 1 and Class 2.

The Class 1 type operates at a maximum power of 100mW and has a signal range of up to 100m.

The Class 2 type operates at a maximum power of 2.5mW and has a range of up to 10m. It allows for longer battery life as the power consumption is low.

Comparison between Wireless Bluetooth Earbuds and other Wireless Earbuds

Wireless Bluetooth EarbudsWireless Earbuds
Only Radio Waves are used to transmit audio signalsBoth Radio and Infrared Waves are used to transmit audio signals
Range of up to 30 feetRange up to 300 feet
Compatible with all Bluetooth-friendly devicesMostly compatible with the same brand devices
Time lag between transmitting and receiving an audio signalNo such latency

Wireless Bluetooth Earbuds Suggestions

Here are a few suggestions:


What is a Codec?

Codec is basically the standard of the digital stream transmitted to your headphones that determines how a signal is encoded, compressed, decoded, and decompressed. Nowadays, a codec is incorporated with Bluetooth.

What are True Wireless Earbuds?

The True Wireless Earbuds are the newest kind of Earbuds that have absolutely no wires to disrupt your listening sessions. The Bluetooth signal is transmitted to the primary bud which then transmits it to the secondary bud.

Are Bluetooth Earbuds wireless?

Bluetooth Earbuds don’t have a wire that connects to the audio source but they may not be truly wireless. The two earbuds might be connected to each other with a wire.

What is Infrared Audio Transmission?

IR waves are electromagnetic waves in the frequency range of 300 GHz to 430 THz. They have shorter wavelengths as compared to RF waves and thus limit the transmission range to 10m. That’s why Bluetooth technology does not use IR transmission.

What is ASK modulation?

The Amplitude Shift Keying is a type of modulator in which the amplitude of the carrier wave is altered. It is commonly used to transmit digital audio over optical fiber.


From the above-mentioned points, we have established that Wireless Bluetooth Earbuds transmit digital audio signals using radio waves with PSK modulation.

Now that you know how wireless earbuds works, have you ever wondered how wired headphones work? They work using headphone jacks. Never heard of it? Read this article: Types of Headphone Jacks: Everything You Need To Know

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