Why does my phone have background noise?
Background noise refers to any ambient sounds that can be heard during a phone call. This unintended noise can be caused by various factors originating from the surrounding environment, the phone’s hardware, software issues, network connection, or the phone user’s actions. Background noise is an annoyance during phone calls because it makes it harder for both parties to clearly hear each other. The unwanted sounds get mixed into the phone call audio, obscuring the intended speech coming through the microphone.
Microphone Quality
The quality of the microphone can have a significant impact on the amount of background noise picked up. Lower quality microphones tend to be more sensitive and pick up more ambient sounds compared to higher quality ones. As Quora explains, “Harmonic distortion — the microphone starts to overload in some frequencies at relatively low levels; Noise — hiss, crackle and pop. Bad quality mics exhibit this” (Source). Cheaper mics often lack noise cancelling features and insulation, making them more prone to interference. Upgrading to a better quality microphone with directional pickup patterns and noise reduction can help minimize background sounds being captured.
Network Connection
A weak cellular or WiFi signal can often cause unwanted static or background noise during calls. This occurs because low signal strength leads to packet loss and audio distortion as your phone struggles to maintain a stable connection.
WiFi networks should generally have a minimum signal strength of -67 dBm or higher for clear audio quality. Levels below -67 dBm may result in choppy audio or static sounds. The noise level on a WiFi network should also ideally be below -92 dBm. High noise reduces the signal-to-noise ratio and makes it harder to isolate the clear audio signal.
Similarly, cellular networks with 1 or 2 bars of signal strength tend to have higher instances of background noise compared to 4-5 bars of signal. Phone calls rely on a strong cellular connection to transmit high quality audio in both directions.
If you are experiencing background noise on calls, first check if you have a poor WiFi or cellular signal in that location. Moving closer to the router or stepping outside for better cellular reception may help reduce the background noise.
You can also refer to sources like this CNET article for recommended WiFi signal strength and noise levels.
Surrounding Environments
Your phone’s microphone is designed to pick up all the sounds around it and transmit them over a call or recording. Loud, echoey, or windy environments can increase the amount of ambient noise that the microphone picks up [1]. For example, talking on your phone outdoors on a windy day will likely result in the microphone picking up a lot of wind noise. Similarly, having a conversation in a large, echoey room may result in more reverberation being transmitted. The microphone does not discriminate between your voice and loud background noises, so the louder and noisier the environment, the more unintended sounds will be transmitted by your phone’s microphone.
Some common surrounding environments that can contribute to unwanted background noise during calls include busy public spaces, windy locations, echoey rooms, and places with loud machinery operating. The microphone picks up all these ambient sounds and relays them to the other caller. Using your phone in a quiet, enclosed space helps reduce the background noise from your surroundings.
References:
- [1] https://www.francisaudiology.com/blog/understanding-background-noise-how-it-affects-your-hearing
Proximity Effect
The proximity effect refers to the phenomenon where microphones tend to pick up more bass frequencies when the sound source is very close to the microphone. This is due to the physics of how sound waves interact with the microphone’s diaphragm and internal components when the source is near the capsule.
On cell phones, the main microphone is located very close to the user’s mouth when taking calls or recording videos. When speaking too close to the phone, the proximity effect causes an unnatural boosting of bass frequencies in your voice. This can exaggerate and amplify sounds like breathing, pops, wind noise, and lip smacks during speech. The result is an unnatural, boomy, and bass heavy sound quality.
To avoid excessive proximity effect, try holding your phone 6-12 inches away from your mouth when speaking during calls or recordings. This gives a more natural sound by reducing the bass boosting phenomenon. You can also enable high-pass filter settings in your phone’s camera app to filter out lower frequencies and reduce the emphasis on breaths, pops, and rumble noises.(Source 1, Source 2)
Phone Cases
Certain phone case materials and designs can muffle or dampen the microphone on your phone, leading to background noise during calls. Cases made of thicker, dense materials like leather and plastic tend to block more sound from reaching the microphone. Designs with front flaps or folio styles that cover the back of the phone are also more likely to cause muffling issues.
As this Reddit user describes, folio-style iPhone cases can block the back microphone and cause the voice to sound muffled on calls: “Phone case causing muffled phone calls. Any good …. Apple community members also report issues with certain cases blocking the mic on iPhones and making recordings sound muffled: Case blocking mic on iPhone 8, 8Plus, & X.
To prevent microphone muffling from your case, look for slimmer, minimal cases made of soft and flexible materials like silicone, TPU, or soft plastic. Cases marketed as having “acoustic transparency” are also less likely to block sound and dampen call quality.
Phone Settings
The settings on your iPhone allow you to enable features like noise cancellation that can help reduce background noise during calls. You can go to Settings > Accessibility > Audio & Visual to adjust these settings.
For example, you can turn Phone Noise Cancellation on or off (see https://support.apple.com/guide/iphone/adjust-audio-settings-iphb80ab7516/ios) to reduce ambient noise picked up by the microphone. This feature uses machine learning to filter out background sounds. The noise cancellation setting is available on iPhone models up to the iPhone 12 but was removed in iPhone 13 and later (see https://www.verizon.com/support/knowledge-base-209489/).
There are also options in Accessibility settings to adjust audio frequencies, tone, and amplification which can make voices more clear and audible during calls. It’s worth exploring your iPhone’s audio and accessibility settings to optimize them for your particular needs. Having the right configuration enabled can significantly reduce background noise and improve call quality.
Phone Model Differences
Phones from different manufacturers and even different models can vary significantly when it comes to microphone quality and background noise pickup. This is due to differences in microphone hardware, audio processing software, and overall design.
For example, according to a microphone comparison test by David Lee King (https://davidleeking.com/smartphone-microphone-comparison/), the iPhone 7 Plus had noticeably lower background noise compared to a Samsung Galaxy S7 when using their built-in microphones to record speech outdoors. The iPhone isolated the speech audio and filtered out ambient background noise better than the Galaxy.
Comparing across brands, one scientific study (https://www.sciencedirect.com/science/article/pii/S0892199722003125) found that iPhones captured speech with lower background noise in both close talking and hands-free use cases than Android phones from Huawei and Samsung. The study concluded that the iPhone had superior noise reduction abilities for speech recording.
Even among different iPhone models, there are variations in microphone noise handling. According to microphone tests on YouTube (https://www.youtube.com/watch?v=_lxNJ1735ZY), the iPhone 11 Pro Max had lower background noise compared to older iPhones when recording video, likely due to its triple microphone array. Newer phone models tend to improve on isolating speech from ambient noise.
Software Issues
Issues with the phone’s operating system or certain apps can sometimes cause background noise during calls. One common culprit is software bugs that cause interference on call audio. For example, some Android users have reported a high-pitched static sound occurring due to a software glitch that sends static to the other caller until the phone is rebooted. Updating to the latest OS version can sometimes resolve such bugs. Additionally, certain apps may cause interference if they use audio channels improperly. Trying to determine if a specific app triggers noise by testing calls with that app force closed can help isolate the issue.
Reducing Background Noise
There are several tips you can try to minimize background noise during phone calls. First, according to RingCentral, you can enable noise reduction features on your smartphone or phone service which are designed to suppress ambient sounds. On iPhones, enable Voice Isolation mode in Control Center to focus the microphone on your voice. For Android, check if your phone model has a Background Noise Suppression setting. You can also adjust microphone settings in apps like Zoom.
Second, Lifehacker recommends choosing a quiet environment without much background noise for important calls. Close doors and windows to minimize external noises from traffic, construction, wind, etc. Turn off any music, television or talk radio. Ask other people nearby to give you some quiet space.
Finally, use headphones designed to block out sound, especially noise cancelling headphones. The microphone will be positioned closer to your mouth, allowing it to better pick up your voice over the ambient noise.