The History of the Headphone and Earphone

As an artist and author, I listen to a lot of audio books. That led me to worry about my hearing as I noticed different headphones and earbuds sounded differently. I sometimes think I listen to them too loudly.

I decided to do some research and went down a rabbit hole. This is what I discovered about headphones, which by the way were invented by Beyerdynamic and later improved by David Clark.

Headphones date all the way back to the invention of the telephone. Because of the weak electrical signals of the early instrument, small speakers were placed close to the ear so the signals could be heard. That speaker was then hung from a headband, which left the hands free. Then, as radio use in airplanes became a standard, a second speaker was added to the headband to help block out the ambient noise in airplane cockpits and the headphone was born.

Beyerdynamic is commonly accepted as being the inventors of the original headphones back in the late 1930s. It was the first company to market headphones to the public.

In 1975 the David Clark company developed the Active Noise Attenuating headphone which added a whole new dimension to listening. That device eliminated or greatly reduced ambient noise for the listener by electronically flipping the noise fingerprint (the wave shape) 180-degrees and playing the resulting sound in real time to the ear-side of the headset, virtually eliminating the noise to the listener.

Applications

Headphones and earbuds are normally a separate piece of a listening device. Some can be plugged into your device with a jack, while others use wireless technology like Bluetooth. Typical products to which they are attached include the mobile phones, smartphones, CD players, digital audio players (MP3 player), personal computers, and laptops. Headphones can also be used with gaming consoles.

Another application is in the professional audio sector. Here, headphones are used by club DJ's and sound engineers for bands to monitor channels independently from what the public hears. An effect can also be previewed this way. In most professional sound studios DJs use a pair of headphones when talking in the microphone while the speakers are turned off, for reduced feedback and monitoring of their own voice. In the studio, musicians will use headphones to play along to already recorded sections of a song. Used in live video settings, the noise cancelling mic and earpiece allow video camera operators and the show producer/control booth to hear and be heard at a whisper without disturbing the audience.

The two common connectors are 1/4" and 3.5 mm plug. Headphones designed for home stereo systems and recording studios use the older 1/4" connector. The smaller 3.5 mm plug is more common in personal listening devices. This 3.5 mm connector is more prevalent today due to the popularity of portable music devices. Most professional settings still use the larger 1/4" style connector however.

In theory, all microphones are speakers and vice-versa. People can use a microphone as a speaker or the left channel of a pair of headphones for a microphone. However, microphones and headphones are different in frequency response. Headphones, especially more expensive ones, will have a large bass response but thin mids and highs. Microphones will sound very poorly detailed in the high end, and will sound light on the bass end. Therefore, while it is not fully necessary, it is recommended that microphone are to be used as microphones and headphones are to be used as headphones.

Benefits and Limitations

A common use of headphones is for listening to recordings privately while in a public setting, such as the subway. high quality headphones can actually produce sounds that are equivalent to the most expensive consumer-level speakers on the market for much cheaper.

Good headphones, such as those you can find reviews for on this neat headphone review site, with high-quality circuitry can have offer an extremely flat low-frequency response all the way down to about 20 Hz.

Headphones can also be useful for video and computer games that use 3D positional audio. This helps players judge the position of an off-screen sounds, which is very important in modern day VR.

In addition, headphones can have an ergonomic benefit over the traditional handset at office desks. They save space and many new models are wireless. They also allow call center agents to maintain good posture instead of tilting their head sideways to cradle a handset. You can also have a room full of people using computers to mix audio tracks all at the same time.

Potential Dangers

The ability to listen to music at high volumes so close to your eardrum has been a problem for decades. With earbuds gaining popularity, it has become an even more dangerous scenario. Headphone volume for normal non noise-canceling models has to compete with background noise, especially in excessively loud places such as public transportation hubs. By pumping up the volume in your headphones to drown out external noises, it's all too easy to reach dangerous and damaging volumes.

Due to many consumer protection groups focus on the hearing dangers that headphones and earbuds produce, there has been a lot of effort to produce quality equipment that does not injure users. Sony's AVLS feature corrects differences in track volumes as they are being played, and Apple's Sound Check normalizes the peak volumes of selected tracks in iTunes. Also, one may manipulate the volume tags, or Replay Gain, of MP3s; this method must be manually done by the user using 3rd-party software, but is regarded to provide better consistency than the above options.

Another common risk to headphone and earbud use is the inability to hear what is happening around you. Biking on a busy street while wearing headphones is much more dangerous than biking without headphones for example.

Though still dangerous, earbuds are generally believed to be safer than open-air headphones for use in noisy environments. The reason for this is that much of the external noise which is usually heard while using earbuds, therefore allowing the user to listen at lower volumes without having to turn up the listening device (possibly to unsafe levels) to compete with background noise (a passive counterpart to active noise cancelers, which use circuitry and destructive wave interference to attenuate sound). Manufacturers of earbuds quote that their products reach an isolation level of -30-40 dB, while noise cancelers isolate by a degree of -15-20 dB. Closed and noise-cancelling headphones can have a similar effect, although sound attenuation of the latter is usually limited in frequency range and amplitude: closed headphones do not isolate low frequency sounds very well, and noise cancelers do not attempt to attenuate high-pitched sounds.

I ended up going a little deeper into this than I anticipated, but that's how we learn about the world we live in today. History, no matter how great or small, shows us how we got to where we are. It's not just about politics, but about every little aspect of our lives we often take for granted.