What is In-ear Detection of TWS Earphones?

What is In-ear Detection of TWS Earphones?
 

As we all know, in-ear detection of AirPods Bluetooth headsets is a special feature. Put on the earphones to play the song, remove the earphones and stop playing the song.

This function can bring users a very user-friendly experience. When the user puts on the headphones, the music will continue to play. When the user removes the headphones, the music will pause. This function can effectively save power to increase the use time for headphones.

Right now there are 2 different in-ear monitoring functions in the market. One is physical in-ear monitoring(We can also say physical in-ear detection or Photo sensory in-ear detection), another one is optical in-ear monitoring (We can also say optical in-ear detection or Somatosensory in-ear detection).

Today let’s talk more about the in-ear detection.

1, What is the difference between them?

Physical In-ear Detection  Physical in-ear detection is through a capacitive sensor that senses the temperature of the human body, when you remove the headphones, the temperature is gone, it automatically recognizes and then stops playing the song; when you put on the headphones, the temperature increases and starts playing the music.

Optical In-ear Detection  Optical in-ear detection is identified by the light sensor, as long as the position of the headphones light sensor is blocked, it can continue to play the song. Removing the headphones, it will automatically identify and stop playing the music.

We all know that light travels much faster than temperature, and temperature fluctuations are greater in summer and winter, sporting and stillness, which means physical in-ear detection  headphones will disconnect in winter, especially in the north, with physical in-ear detection headphones having a slightly higher (but not very noticeable) delay than optical in-ear detection. With physical in-ear detection headphones at sporting being prone to disconnect if the earphones are at the wrong position.

Basically, the optical in-ear detection is better than the physical in-ear detection. But it does not mean that the physical in-ear detection is bad. If you don’t need this function, you can just turn it off. Due to the cost, optical in-ear detection tends to be much more expensive than physical in-ear detection, so how to choose depends on your financial budget.

2. If physical in-ear detection or optical in-ear detection is added to the earphones, how much will the cost be added?

This issue can be addressed in terms of both the actual added cost of the product and the aftersales cost. For example, in the case of Apple Airpods II, the basic cost of the optical sensor is 0.86USD. The assembly work is cumbersome and complicated. The assembly cost and the defect rate cost together may be over 1.45USD. On the one hand, the optical in-ear detection is easy to be triggered by mistake, on the one hand, it will pick the ear, and then the defect rate is relatively high during the production process, which is easy to get customer complaints.

3. The advantages and disadvantages of the two functions

Headphones that are not positioned properly, or that slip out while exercising, can easily trigger induction and cause a bad experience.

Because each person's ear structure is different, there is a certain probability that it will be difficult to touch the physical sensor no matter how you put it in your ears. This probability is very low, but there are still such invalid ears.  Physical in-ear detection has a lower defect rate and low cost, so there are many physical in-ear detection earphones on the market.

If the headphones are not positioned properly, or if the headphones slide out during exercise, it is easy to trigger the induction, resulting in a bad experience.

The shortcomings of optical sensing are easy to fail under strong light, leading to false triggering. At present, the products of big brands in the market are all using optical in-ear detection.

In short, products with two functions may cause customer complaints and increase cosy due to the above shortcomings.

4. If a product does not have in-ear detection function, can this function be added later? Or need to develop new products?

The optical sensor has to be defined at the beginning when we design a product, set aside in the structure (PCB and housing)first.

Physical can barely be added later.

So above are the details of two different in-ear detection functions. Hope you can distinguish the difference when you got products.