How to Fix Bad Phone Call Quality
When phone calls sound scratchy, muffled, or keep cutting in and out, the conversation becomes frustrating for both sides. The problem might be a dirty microphone, a network issue, a software glitch, or an actual hardware failure. Working through the possibilities in order — from the simplest fixes to the more involved ones — usually identifies the cause without needing to take the phone in for repair.
Clean the microphone and speaker
This fixes more call quality problems than most people expect. The microphone opening on the bottom of your phone and the earpiece speaker at the top accumulate lint, dust, and pocket debris over time. Even a small amount of material partially blocking the microphone hole can make your voice sound muffled or distant to the other person.
How to clean
- Microphone (bottom of phone): Look at the small hole or holes on the bottom edge, usually near the charging port. Use a clean, dry, soft-bristled brush (a new toothbrush works well) to gently brush across the opening. Do not push anything into the hole — you can damage the microphone membrane. If debris is visible but stuck, a single short burst of compressed air from a few inches away can dislodge it. Do not use liquid
- Earpiece speaker (top of phone): The thin slit at the top of the screen where you hold the phone to your ear collects similar debris. Brush it gently in the same way. On iPhones with Face ID, the earpiece is a narrow slot above the display — it gets clogged easily
- Screen protector interference: Some tempered glass screen protectors cover or partially block the earpiece opening. If call audio improved when you removed the protector, the protector was the problem. Replace it with one that has a proper cutout for the earpiece
Remove your case temporarily
Some phone cases block or partially cover the microphone holes. This is especially common with thick rugged cases, wallet cases, and cases that were designed for a different phone model. Remove the case entirely and make a test call. If the call quality improves immediately, the case is the problem — switch to a case designed specifically for your phone model that has properly aligned cutouts for all microphones and speakers.
Test with different call types
How the call is placed determines what is handling the audio, and that tells you where to look for the problem.
- Regular phone call (cellular): Audio goes through your carrier's network. Quality depends on signal strength, network congestion, and the phone's cellular modem
- Wi-Fi calling: Audio goes through your Wi-Fi network and internet connection. Quality depends on your Wi-Fi signal and internet bandwidth
- VoIP apps (WhatsApp, FaceTime Audio, Telegram, Signal): Audio goes through the app's servers via your internet connection. Quality depends on both your internet and the other person's internet
- Bluetooth call: Audio goes to your Bluetooth headset or car system. Quality depends on the Bluetooth connection and the headset's microphone
If only one type of call has poor quality, the problem is specific to that path. If all call types sound bad, the problem is the phone's hardware (microphone or speaker).
Check your cellular signal
Weak cellular signal is the most common cause of calls cutting in and out, dropping, or having robotic-sounding audio. The signal strength indicator (bars) gives a rough idea, but for a more precise reading:
- iPhone: Open the Phone app and dial
*3001#12345#*and press call. This opens Field Test mode, which shows signal strength in dBm (decibels-milliwatt). -50 to -80 dBm is strong. -80 to -100 is moderate. -100 to -120 is weak. Below -120 is poor and calls will suffer - Android: Settings, About phone, Status (or SIM status), and look for Signal strength. Same dBm scale applies
If your signal is weak:
- Move closer to a window or go outside. Building materials (especially concrete, metal, and energy-efficient windows) block cellular signals significantly
- Switch between carriers if you have dual SIM — one network may have better coverage at your location
- Enable Wi-Fi calling as a fallback. Most carriers support this: Settings, Phone, Wi-Fi Calling (iPhone) or Settings, Connections, Wi-Fi Calling (Samsung/Android). When enabled, calls route through your Wi-Fi network when cellular signal is weak
Toggle VoLTE
VoLTE (Voice over LTE) carries phone calls over the 4G LTE data network instead of the older 2G/3G voice network. It generally provides better call quality, but if it is malfunctioning on your phone or your carrier is having VoLTE issues, it can cause static, echo, or one-way audio.
- iPhone: Settings, Cellular, Cellular Data Options, Voice and Data. Switch between LTE with VoLTE and LTE without VoLTE. If VoLTE was on and calls were bad, try turning it off and making a test call
- Android: Settings, Connections, Mobile networks, VoLTE calls (toggle on/off). The exact path varies by manufacturer
If turning VoLTE off fixes the call quality, the issue is between your phone and your carrier's VoLTE infrastructure. You can leave it off, or try toggling it back on after restarting the phone — sometimes the connection re-establishes cleanly.
Restart the phone
A restart clears the phone's audio processing pipeline, resets the cellular modem's connection to the tower, and stops any background processes that may be interfering with call audio. This is a simple step but it resolves a surprising number of intermittent call quality issues — especially ones that developed gradually or after the phone had been running for weeks without a restart.
Update carrier settings and software
- iPhone carrier settings update: Settings, General, About. If a carrier settings update is available, a prompt will appear. These updates contain fixes for connectivity and call quality that are specific to your carrier
- Software update: Check for and install the latest OS update. Audio processing and modem firmware are included in system updates, and call quality improvements are common in point releases
Reset network settings
If the problem persists, resetting network settings clears all cellular, Wi-Fi, and Bluetooth configurations and forces the phone to start fresh with its network connections. This fixes persistent call quality problems caused by corrupted network configuration without affecting your apps, photos, or other data.
- iPhone: Settings, General, Transfer or Reset iPhone, Reset, Reset Network Settings. You will need to re-enter Wi-Fi passwords afterward
- Android: Settings, System (or General management), Reset, Reset network settings
Check for hardware problems
If cleaning, software fixes, and network resets have not improved call quality, the hardware may be damaged. Signs of microphone or speaker hardware failure:
- People cannot hear you at all on calls, but you can hear them. The microphone has failed
- You cannot hear callers at all, but they can hear you. The earpiece speaker has failed
- Audio recordings (voice memos, video recordings) sound muffled or distorted. This confirms the microphone is the issue, independent of network conditions
- Speakerphone works but earpiece does not (or vice versa). Different speakers are used for each mode, so one can fail while the other works
- Water exposure history. Even phones rated for water resistance can develop audio problems from moisture reaching the microphone or speaker. Corrosion on the microphone contacts causes intermittent or degraded audio
Call quality help in Marion
If your phone calls consistently sound bad and you have worked through the software and network fixes, Marion Phone Repair can test the microphone and speaker hardware to determine if a component replacement will resolve the issue.