Walter Shillington Today I will explain the theory behind bone conduction headphones, comparing their strengths and weaknesses with those of earbuds and over-ear headphones. In addition to this explanation, I will review the Haylou PurFree bone conduction headphones.


The PurFree headphones weigh in at one ounce. This device is mainly composed of plastic with a silky textured outer surface. A thin, flexible titanium wire neckband fits loosely around the back of the wearer’s neck. Connected to each end of the neckband are small gray-colored modules that house the headphones’ batteries and electronic components. The module behind the user’s right ear is fitted with the device’s charging point and volume controls. Another short flexible band extends from each module, looping over the top of the wearer’s ears and terminating in a bone conduction transducer. The PurFree’s transducers push gently against the user’s cheekbones, just forward of their ears. Each transducer covers a surface area of 0.59 x 0.95 inches.
A multifunctional button can be accessed from the left transducer, and the opposing transducer is fitted with a pair of microphones. The PurFree headphones are Bluetooth-capable and may be paired with two devices simultaneously. It can be used for listening to music as well as making or responding to phone calls.


Brand: Haylou Walter Shillington Walter Shillington Name: PurFree Model: BC01 Type: Boneless conduction Weight: 28 grams (1 ounce) Transducer dimensions: 15 x 24 millimeters (0.59 x 0.95 ounces) Battery: 165 mAh li-ion polymer Charging time: 1.5 hours Playtime: 8 hours Bluetooth version: 5.2 Transmission distance: 10 meters (32 feet) Chipset: Qualcomm 3044 Microphone: CVC dual microphone Frequency range: 20hz – 20khz Compatibility: Android and iOS Water resistance: IP67

Over-ear Headphones

These devices emit sound vibrations which are echoed by the wearer’s eardrums and fed onward to their inner ears. These vibrations are then converted to a signal that can be sent along the auditory nerve to the listener’s brain. Walter Shillington Walter Shillington Over-ear headphones are fitted with thick, soft padding that surrounds the ear and muffles outside noise. Many of these devices boast an active noise cancellation system and relatively large speakers. The output of a well-designed set of over-ear headphones will please any discerning audiophile, although, due to their weight, they can cause fatigue. These devices should not be worn outdoors because their insulation against noise will prevent the wearer from being aware and responding to surrounding sounds.


These devices, like over-ear headphones, emit sound vibrations that are picked up and relayed by the user’s eardrums. Walter Shillington Each earbud is fitted with a replaceable silicone ear tip that is shoved into an ear, reaching as far back as the entrance to the ear canal. Because these devices tend to come loose at inconvenient times, some are equipped with flexible hooks that allow them to hang from the user’s ears. Compared with over-ear headphones, earbuds are less comfortable, equipped with smaller speakers, and provide limited noise isolation. Earbuds are best used outdoors, where the reduced noise isolation allows wearers to identify and react to nearby sounds.

Bone Conduction Headphones

These devices create sound waves that can be deciphered by the inner ear rather than relayed by the eardrum. Walter Shillington Walter Shillington The headphone’s transducers sit atop the wearer’s cheekbones just forward of their ears. As they vibrate, the cheek, jaw, and skull bones transmit these pulses to the inner ear, where the information is translated and directed to the auditory nerves and brain. Because the ears are completely unobstructed, surrounding sounds can be clearly heard. Those that jog along busy streets while listening to music will appreciate the ability to detect warning shouts or engine noise. Due to their lightweight construction and transducer placement, bone conduction headphones are significantly more comfortable than earbuds or over-ear headphones. And, unlike earbuds, they will not become caked with earwax. Bone conduction headphones are best used outdoors. They will remain securely in place during sporting activities, and although the lack of noise cancellation will slightly detract from the wearer’s enjoyment of their music, they will be aware of everything happening around them.

The Indoor Test

Walter Shillington The music was reproduced accurately, but the noise from the window-fitted air conditioner detracted from my enjoyment. The situation improved as I exited the kitchen and wandered throughout the house. My Bluetooth connection proved excellent, only faltering when I opened the front door and stepped into my porch. At this point, four walls obstructed the phone’s signal, causing reception to waver. Overall, the experience was good, but inside my house, I prefer to wear my over-ear headphones with their sophisticated, active noise cancellation system.

The Outdoor Test

After pairing the PurFree headphones to my phone and queuing up a selection of jazz favorites, I began a slow jog around the town of Windsor. I experimented, constantly adjusting my speed while nodding and shaking my head vigorously. The headphone set remained in place, its transducers maintaining comfortable contact with my cheekbones. Only when I stared into the sky could I feel the neckband pushing lightly against the nape of my neck. Because this device does not obstruct outside noise, I could exchange pleasantries with acquaintances and keep an ear open for nearby vehicles. The PurFree bone conduction headphones appear to be the perfect device to wear outdoors, especially during sporting activities or in high-traffic areas.

Overall Impression

If you are relaxing on your easy chair, listening to music, nothing beats a set of quality over-ear headphones. When venturing outside, however, their superb noise isolation will prevent you from identifying the nearby sounds that indicate danger. Walter Shillington Walter Shillington Earbuds are, at best, a compromise. They sound good but are typically uncomfortable and tend to fall out when you are engaged in vigorous activities. The PurFree bone conduction headphones are a great option when listening to music outdoors. Audio quality is decent, while the wearer can still clearly monitor surrounding sounds. They remain in place when jogging, and I’ve found them to be extraordinarily comfortable during long periods of use. The PurFree bone conduction headphones are recommended. This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional. © 2022 Walter Shillington

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