How Do Wireless Headphones Work?

Headphones became a necessary tool in our daily lives. We use it for work, in school or for recreation. And as technology evolves, so do they.

Wireless headphones were first introduced in the ’60s. But it was in 2004 that Bluetooth wireless headphones came onto the market. These devices were based on a technology that accepts signals from various sources and forwards them by converting them into sound.

It gained popularity among audio consumers and professionals. The upgrade revolutionized personal audio listening. Connecting to different devices became easy. Now, if you are wondering how wireless headphones work, read on. In this article, we will discuss what wireless headphones are, how they work, how to use them, and more.

Wireless Headphones: How Do They Work?

To most of us, it is a complete mystery as to how wireless headphones work. With hardwired headphones, the concept is much easier to fathom.

The electrical energy flows from the smartphone through the plug going up the wires and to the headphone’s driver which is converted into sound. However, with wireless headphones, how does audio or sound get transmitted from your device through the air and into the wireless headphone?

Wireless headphones are incredibly complex. Bluetooth technology replaced the wires connecting to the headphone. Therefore, it became “wireless”. Now, wireless transmission is possible because Bluetooth devices utilize low-power radio signals.

Note that these headphones are somewhat thick on the ground. These headphones have built-in receivers to accept wireless waves that bring the audio signal to run the headphone drivers. The term for this “wireless signal” is called the carrier wave.  

From Sony UK

The audio signal is converted by transmitters into a wireless format or a carrier wave and then transmits the wireless signal through the air. This audio signal referred to here is the modulating signal. It is converted into a carrier wave transferred wirelessly to the receiver. 

The wireless format or carrier waves utilized in transferring signals of a wireless headphone either comes in the RF range or the IR range. A carrier wave is a single-frequency wave within the ranges mentioned earlier (radiofrequency and infrared frequency range). Generally, audio signals are composed of frequencies that have an audible range of 20Hz – 20,000 Hz.

The function of the wireless receiver is to interpret the carrier wave and decipher the modulating signal or the audio coming from the wave. It is designed to recognize the specified carrier wave frequency.   

A digital audio signal is usually converted to an analog audio signal. Then, the converted audio signal is expanded to drive the headphone drivers accurately.

Wireless Earbuds or IEMs: How Do They Work?

Wireless earbuds or in-ear monitors (IEMs) work in much the same way as their full-size wireless headphone counterparts. However, since space is a limiting factor – a lot more engineering processes go into developing wireless earbuds/IEMs. As a result, their costs can be relatively high despite their miniature size. See our top recommendations for best wireless workout IEMs.

From Branch Education

Do Wireless Headphones Need Batteries?

Remember that regardless of the types of wireless headphones, being wireless means the device is active. In other words, they need the power to work correctly. To maintain its function as a wireless device, the headphone also requires internal batteries for the power supply. Although it is common for wireless headphones to have built-in rechargeable batteries, others may need AA or AAA batteries.

Aside from the method mentioned above, wireless headphones also act similarly to hardwired headphones.

Modulating Signals and Carrier Waves Explained

To fully grasp the concept of how wireless headphones and audio transmission works, it is essential to know about carrier waves and modulating signals.

As the name implies, the carrier waves carry the audio signal from the transmitter to the receiver. It is an electromagnetic wave that is modified with an information-bearing signal to process wireless transmission. An electric charge will produce vibration and will create electromagnetic waves. The vibration from electric charge has its components called electric and magnetic. The electromagnetic waves will take the energy to different places. And this will be the wireless audio from the transmitter to the headphone receiver.

Sound waves are mechanical waves, but electromagnetic waves move through a vacuum without intermingling directly with the medium’s molecules. However, atoms in the medium will still attract electromagnetic wave energy.

Radio frequency bands
From Terasense

Generally, the carrier signals from wireless headphones are either infrared waves or radio waves. The infrared waves are usually rare. The radio frequencies or RF range from 30Hz to 300 GHz, while Infrared frequency or IS range from 300 GHz to 430 GHz.

Whether IR or RF, the carrier wave is considered as the sinusoidal wave with a signal frequency. The transmitter is used to transmit the single-frequency carrier wave while the receiver is tweaked to accept the single-frequency wave carrier. Hertz is used to calculating the cycles per second. 

Wireless headphones provide an excellent wireless range of up to 300 ft or 91m because it usually operates near 2.4 GHz radiofrequency.

Meanwhile, the modulating signal modulates or regulates the carrier signal. The carrier wave transmits this signal from a wireless transmitter to a receiver. Wireless headphones have modulating signals, which are audio signals created for the headphone drivers. The modulating signal has various ways to modulate the carrier wave.

How Does Wireless Analog Audio Transmission Work?

Wireless Analog audio signal transmission is a kind of frequency modulation that is considered standard. It is the same transmission used in FM radios. Therefore, radiofrequency FM headphones can function as a mini radio station.

FM operates by modulating the frequency of the carrier wave. The resulting frequency modulated signal from a simple audio sine wave will look something like this:

Diagram shows the difference between the waves of a modulating and carrier signal, and frequency modulation.
From Omni.Sci

Hence, the single-frequency carrier wave should work across a scale of frequencies once modified by the audio signal.  The receiver can collect the bandwidth of a modulated carrier wave. Meanwhile, the audio signal will increase once the receiver of the headphone demodulates the carrier wave frequency. And this process will keep the variation low and concise.

Wireless Digital Audio Transmission Explained

Since the world is going digital, most headphones are now capable of accepting digital audio wirelessly. Digital audio is like a digital version of analog audio. It takes candid snapshots of audio signal amplitude and characterizes them digitally. The audio quality can be verified based on sample rate and bit-depth.

The sample rate is defined as the number of individual audio amplitudes sampled in each second. The expected sample rates ranges are 44.1 kHz and 48 kHz. Hz here is referred to as the second or sample.

Meanwhile, bit-depth is the number of bits utilized to represent amplitude in a sample. If the sample rate and bit-depth are higher, the resolution is excellent. The quality of the digital audio signal is also higher. However, higher sample rates and bit-depth will also need greater power in processing, and the various sample rates may not be consistent with one another.

Process of Bluetooth Transmission of Audio from a Device to Headphones

Most wireless headphones these days are designed with Bluetooth technology. Therefore, you need to know how it works.

The Bluetooth standard is constantly improving. There are different versions available. The people behind this technology – The Bluetooth Special Interest Group and engineers are continually working to ensure cross-compatibility between versions. But pairing two devices with different Bluetooth versions will only get the oldest version’s features.  

If you are a Bluetooth device user, you already know that Bluetooth works by pairing the devices. The pairing is essential for transferring information. Bluetooth network connection is called Piconet. The transfer of data or audio is one-way. The audio device is the one controlling the headphone.

Bluetooth sends digital information through short-range radio frequencies ranging between 2.400 to 2.485 GHz. Meanwhile, Bluetooth headphones transmit the digital audio signal from the paired device. There are 79 different frequencies within the 2.400 to 2.485 GHz to send information. These frequencies can change 1600 times per second. The changes will help to prevent obstruction with other Bluetooth connections. And reduce the risk of interference between Bluetooth devices. If there’s any interference on a specific frequency, it will only last a second.

The PSK or the Pulse-shift keying modulation sends the Bluetooth audio. It is the digital audio of the paired device. The modulation will produce a modulating signal responsible for modulating the phase of a fixed-frequency carrier wave. What it does is vary the cosine and sine inputs in an accurate time. This means that the digital audio signal is transmitted on one of the 79 radio wave frequencies that shift 1600 times each second. 

What is the Optical Range of Wireless Bluetooth Headphones?

Wireless Bluetooth headphones are considered the most advanced wireless versions of headphones. It does not require any kind of transmitter to connect; the only requirement is two devices that support Bluetooth technology.

The optical range of average wireless Bluetooth headphones ranges from 20m to 100m. When it comes to data privacy, Bluetooth transmission is purely private, and before transmitting the information, the headphone and the device will first exchange identification. There is a specific encoding that functions as a protection of data from the interference of losing confidentiality. 

What is the Range of a Wireless Headphone?

Wireless headphones devices range up to 10 to 30 meters, and distance is calculated as an optical distance. Interference may occur and affect the range; hence it is vital to check all the aspects while measuring the range.

Battery Life of a Wireless Headphone

The battery life of a wireless headphone depends on different factors such as the quality, capacity, type, and how often it is used. On average wireless headphones, the battery can last between 25 to 30 hours.

Why is a Wireless Headphone an excellent small investment?

Perhaps the curiosity of how a wireless headphone works lead to questioning why you should choose a wireless headphone? There are good reasons why it is a must-have.

Free from tangled wires or cables. Most people who converted to wireless headphones wanted to get rid of the wires and cables. Wireless means less hassle. You can take it anywhere with you.

Great Sound Quality. Let us all admit it; wireless headphones can have high-quality audio. It is because their technology is constantly improving.

Price difference. Price may not be a good reason to compare wireless and hardwired headphones. Wireless headphones are more expensive than the cabled ones. However, if you compare the quality, capability, and mobility, the wireless is worth more than the actual price. It has additional features, including play, skip, and pause buttons that you can use without holding your device. One more thing, do not forget the sound quality of wireless headphones. However, it depends on your needs.

Compatibility to almost any device. Since wireless headphones are standard nowadays, most smartphones and some devices are compatible with them to use.

Mobility. For someone who is constantly on the move, the wireless headphone is the best device to use. Wired headphones can cause disturbance and a lot of hassles.

How to Use Wireless Headphones

Knowing how a wireless headphone works and why it is an excellent addition to your essential tools, you must also learn how to use it properly. You need to adjust the wireless headphone to your ears, listen and enjoy. But still, we recommend you follow these instructions for using wireless headphones.

1. Check if the battery is fully charged to avoid interruptions.

2. Turn on the wireless headphone

3. Make sure to have a Wi-Fi network to connect.

4. Enable pairing mode

5. Scan to search for a connection.

6. Tap the name of your wireless headphone

How to Connect to a Wireless Headphone

Wireless here means headphones that can connect via Bluetooth, radio signals, and infrared. Wireless headphones can connect with mobile devices or smartphones. The Bluetooth wireless headphone is the standard and common type of headphones used these days. You need to enable the Bluetooth of your smartphone and pair it to the device.

Wireless or Wired Headphones: Which Is Better?

The creation of wireless headphones does not mean hard-wired headphones are entirely obsolete. There are factors you need to consider, and as we mentioned before, your choice depends on your needs or priorities. So here are some comparisons you must consider:

When it comes to pricing, there is a big difference. Since wireless headphones are created with new technology and additional features, it is much more expensive than the wired headphones. Wireless headphones are designed to provide convenience. On the other hand, cabled headphones are cheaper, but it does not mean they are low quality.

From RTings

Sound quality is one of the factors that consumers consider when it comes to buying a headphone. Music lovers and professionals alike who often use headphones are looking for excellent sound quality. There are wired headphones that can compete when it comes to sound quality. Some consider wired headphones better in this aspect. Many of the best sounding headphones only arrive in wired format.

Additional features are also a factor for some consumers when buying a headphone. Models of wireless headphones have advanced features like play, pause, skip, on, and off buttons on headphones. You do not need to get your device from your pocket to touch the controls.

Wireless headphones are fabulous for people who are multitasking and doing a lot of physical activities.

See some of the differences below between wired and wireless headphones:

Wired Headphones:

  • Can connect to an external amplifier
  • Clearer audio
  • Active or passive
  • With wires
  • Can connect to headphone jacks
  • May or may not need batteries to work

Wireless Headphones:

  • Can connect to an audio source wire-free
  • Built-in amplifiers
  • Spottier audio
  • Always active
  • Needs batteries
  • Wireless

Regardless of the differences, wired and wireless headphones work almost the same. Both can take any form factor such as closed-back, headphones, open-back, over-ear, on-ear, and more. And their key components are the drivers. They may differ in methods in getting the audio from the source, but the drivers’ elements are pretty much the same.

What are the advantages and disadvantages of having Wireless Headphones?

Advantages

  • Most wireless headphones come in Bluetooth standard, which means they are compatible with most audio devices today.
  • It does not need tethering to an audio device.
  • Wireless headphones with Class 2 Bluetooth can allow up to 32 ft or 10m range.
  • RF can reach 300 ft or 91 m range or more
  • IR can range up to 10m or 32 ft.

Disadvantages

  • It needs batteries to operate, which means replacement and regular charging is required.
  • Bluetooth standards can quickly drain the battery of the paired device.
  • Expensive
  • There are times connectivity is not easy.

Final Thoughts

Constant mobility and multitasking are just some of the reasons why wireless headphones have been created. Working people are always longing for convenience when it comes to working routines. The emergence of wireless headphones has somehow helped this issue. However, it does not mean wired headphones are no longer helpful. For some reason, some consumers preferred to use wired ones with work. Cabled headphones are cheaper and have better sound quality. Reassess your needs. Why do you think wireless is good for you? Why not wired ones? We hope this article has given you a more straightforward explanation of how wireless headphones work. And, we have provided you some ideas about getting wireless headphones or wired headphones.

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