That tiny hole next to your phone’s charging port may look unimportant, but it actually serves a key purpose: it usually contains a secondary microphone. Most modern smartphones are designed with more than one microphone to improve sound quality in everyday use, even though the extra microphones are nearly invisible and easy to overlook.

These microphones work together to make your voice clearer during calls, reduce background noise, improve audio during video recording, and help voice assistants recognize speech more accurately. In noisy environments—like streets, restaurants, or crowded rooms—the secondary microphone helps filter out unwanted sound so your voice comes through cleanly. Without it, conversations may sound muffled, recordings can lose depth, and voice commands may fail more often.

Because the opening is so small, many people mistake it for the SIM tray release hole and poke it with pins or paperclips. This can damage the delicate microphone membrane inside. If that happens, you may notice distorted call audio, poor noise cancellation, weaker speakerphone clarity, or recordings that sound uneven, quiet, or unclear.

Keeping it clean is simple and safe. Gently brush away dust with a soft, dry brush, or use a light burst of air to remove debris. Avoid inserting sharp objects, even if the hole looks blocked, since even small pressure can cause lasting internal damage. Though tiny, this secondary microphone plays a major role in everyday phone performance, proving that small design details can make a big difference.