Apple patents method that would allow bone conduction to be used on a future version of the AirPods
Bone conduction transmits sounds by using vibrations sent through a person’s jaw and head. The vibrations skip the eardrum and are picked up by the inner ear where they are turned into sounds. This technology is a great replacement for those who are hard of hearing or where a medical reason prevents a person from donning earphones or headphones. It also works underwater where vibrations aren’t stopped by the lack of air.
But there are some issues with bone conduction. One, the latter is only effective at 4,000 Hz and less. Above that level, the quality of the sound deteriorates. Human hearing covers 20 Hz to 20,000 Hz so bone conduction will only work with a small percentage of the human hearing range. In addition, contact with the head is required for this technology to work. This causes a tactile tickling sensation that can be annoying.
The patent, titled “Multipath audio stimulation using audio compressors” envisions separating audio signals into a high-frequency component, a mid-frequency component, and a low-frequency component. The mid and low-frequency signals are processed using a compressor to reduce the dynamic range of the audio and then combined. This component, made up of the combined and compressed mid-and-low-frequency signals, are transmitted via bone conduction. The high-frequency signals are delivered through the air. This allows the audio delivered by bone conduction to hit the sweet spot in terms of frequencies.
The patent was originally filed in May 2018 and has been given the number 10,728,649. Apple receives a large number of patents each year (patent attorneys need to eat too) but that doesn’t mean that every patent the company receives will be used on an upcoming device. According to super analyst Ming-Chi Kuo, the next version of the AirPods is expected to be unveiled before next year’s WWDC (which could be streamed virtually again) in June. The AirPods 3 will have the same design as the AirPods Pro according to Kuo and might use bone conduction to deliver audio.