Although smartphones have undergone significant compaction by making their bodies increasingly uniform and lacking in holes, They continue to have several holes that serve them for a multitude of tasks.. And there are those small perforations that the phone has on the top edge, often in other areas as well. Although it may seem otherwise, they are very important.
Despite the fact that mobile phones were abandoning the ability to be disassembled into pieces in favor of the now common “unibody” bodies (They do not allow the battery to be separated), this progressive tendency to make them more compact and uniform came face to face with the needs of the telephone. For example, those made of metal have separation strips that act as an antenna; The ports are essential and there are a series of holes that cannot be escaped from either. Curiously, the more expensive the phone is, the more holes it usually has.
The key in the holes is the number of microphones
Bottom microphone on the Samsung Galaxy Note 20 Ultra
You may think that the phone is satisfied with including a single microphone to record your voice during calls or videos, but this is not the case: it is common for each manufacturer to add two or three microphones to their devices, even if they are low-end. And of course, those microphones they need to receive the audio without the device itself muffling it; hence the holes.
The holes are made in the body of the phone and on all its faces, both on the sides and at the top or bottom (even on the back). Its purpose is make way for what is captured or sent by the components inside the phone; whether sound, light or data. There is also a hole that has a mechanical function: opening the tray for SIM cards and SD cards.
Each manufacturer can make the holes in the body of the phone in different areas, but the usual thing is that have one at the bottom, next to the USB connector. Specifically, that one is dedicated to the microphone, it is usually one of the most controversial.
Each manufacturer places the holes in the body of the phone depending on how they organize the internal components: sometimes they are on the sides, sometimes on the top and all the way down. The number of holes also varies from one mobile to another
Depending on the area of the phone, the holes made in the metal or plastic body (also in the glass) have different uses. Let’s see which ones.
Upper zone: micro, lighting or infrared
Holes for the secondary microphone, for the infrared emitter and for the lighting sensor (Huawei P50 pro)
Holes can be placed on the upper edge of the mobile to make way for a secondary microphone, for example. Besides, There are brands that place the lighting sensor there Yes, due to the characteristics of the screen, you cannot place it next to the call headset. In this case you can see not only a hole, but also a kind of cover; which leaves space for light to pass through.
One last use for this area of the phone is the infrared emitter. Most of the Redmi and Xiaomi become a remote control: They take advantage of the upper hole to house an infrared emitter. As in the case of the lighting sensor, the hole is protected by a kind of cover (so that light can pass through).
As an extra, there are manufacturers that house the SIM tray on the top edge. In this case, the hole is visible next to the ellipse that shows said tray. There are also phones that place the secondary speaker output in this area.
Sides: SIM tray
Side hole for the SIM tray on iPhones
It is not common for manufacturers to include holes to house microphones or other sensors on the sides of the phone, neither on the left nor on the right. Yes it is quite common accommodate the SIM tray in these areas; so the hole will appear next to the ellipse of said tray.
Lower area: USB, speakers and microphones
Micro next to the SIM tray (Xiaomi 11T). Is there really no better place?
The bottom edge of the phones is a space dedicated to the connection port (USB C, micro USB or Lightning, depending on the brand and model). In addition, the holes for external speakers are also usually located here, a series of strips or holes through which the sound comes out.
It is relatively common for a hole right next to the USB port: This is dedicated to the secondary microphone, an element that mobile phones use to apply noise cancellation to calls.
As an addition, the SIM tray can also be located here. As in the rest of the areas, the extraction hole is next to the ellipse created by the tray in the body; with the problem that The hole for the secondary microphone can be confused with that of the card extraction tray. It has happened to us more than once, we can attest to it.
Rear area and on the lenses: microphone
Rear microphone on the Google Pixel 6
Higher-end mobile phones usually include a hole in the lens area, this is the case in most iPhones, for example. This hole is for the video recording microphone, an element that allows you to zoom audio to recordings; or improve sound with omnidirectional audio recording, for example.
Mobile phones include several microphones because this improves call quality, voice detection by the assistant and recordings
Holes are typically used to allow phone microphones to pick up outside audio without metal or plastic muffling the sound. Its usefulness is more than justified.
