iPhone のマイクが動かない?完全ガイド

iPhones have three microphones: bottom, front, and rear. Any one of them failing produces different symptoms. This guide explains how to test each, fix common software issues, and decide when the problem is hardware.

Common Causes of iPhone Mic Issues

The most frequent cause: a case or screen protector covering one of the microphone grilles. Cheap cases often misalign with the iPhone's mic ports. Remove the case and test again: many "broken" mics are actually muffled by accessories.

Second most common: app-specific permission denied. iOS asks for mic permission once per app, and an accidental "Don't Allow" stays permanent until manually changed.

Check App Microphone Permissions in iOS Settings

Settings → Privacy & Security → Microphone. Every app that has ever requested mic access appears with a toggle. Verify the affected app (WhatsApp, Zoom, Safari, etc.) has the toggle on.

If an app isn't in the list, it's never requested mic access. Open the app and try to use the mic: iOS will prompt, and the app appears in Privacy after the prompt.

Clean the Microphone Grille Safely

Pocket lint, dust, and dried sweat accumulate in microphone grilles over months. Use a soft-bristle brush (or dry toothbrush) to gently clean each grille. Avoid compressed air at high pressure: it can damage the diaphragm.

The bottom mic is between the lightning port and the speaker. Front mic is in the speaker grille at the top of the screen. Rear mic is next to the cameras.

Test Each Microphone on Your iPhone

Voice Memos app: records via the bottom mic. Camera (video): uses the front mic when recording front-camera video, rear mic for rear-camera video. Test each in turn and listen back for clear audio.

For a deeper test with visual feedback, use our free in-browser tester:

Disable Noise Cancellation

iPhone has a "Phone Noise Cancellation" feature that can over-aggressively cut your voice on calls. Settings → Accessibility → Audio/Visual → toggle off "Phone Noise Cancellation". Test a call.

iOS Update Fixes and Resets

iOS updates occasionally fix or cause mic issues. Settings → General → Software Update: install any pending updates.

If nothing works, back up your iPhone first, then reset all settings (Settings → General → Transfer or Reset iPhone → Reset → Reset All Settings). This wipes Wi-Fi, Bluetooth, and preferences but keeps your data: and it fixes a surprising number of weird issues.