Technology has come a long way since the first telephone. We can watch the newest episodes of our favorite TV shows in high resolution on a tiny piece of glass that we carry in our pockets. So why then, with all of this impressive technology enriching our everyday lives, do we still have to deal with microphone problems on voice calls?
In particular, the microphones in our devices and headsets cause the most frustration when we’re trying to make ourselves heard. In this article, we look at the reasons for poor microphone quality. If you came here in search of help with other types of microphones, for recording, podcasting, or live performance, check out the video above. Then come back and read this article!
Editor’s note: this article was updated on April 20, 2021, for technical content.
What is the audio transmission process?
Whether it’s a traditional cell phone call or a Voice over Internet Protocol (VoIP) call, your voice goes on quite a journey when you call someone. First, there’s the acoustic path from your mouth, and the conversion to an electrical signal done by the microphone itself, followed by the conversion to digital bits (1s and 0s). Then there’s signal processing, data reduction and compression, transmission, and a bunch of data relays before it even reaches the device at the other end.
And that’s in the simplest case. There may be multiple wireless transmission protocols along the way, including Bluetooth at one end or the other, or both! Every link in this chain can affect the quality of the signal received by the person you’re talking to. Let’s follow the path and find out which of these you have control over, and which you don’t.
What should you check for first to solve your microphone problems?
If you have issues with your mic, the first thing you should do is take a close look at the mic port to see if there is anything obstructing it. If dust and dirt are in the way, take a moment to carefully clear it out. All good? Right, then let’s move on.
Even if you take great care of your hardware, it’s bound to accumulate dust and debris. We carry devices and headsets around with us everywhere in pockets and in bags and expose them to all kinds of environments. Microphones in modern electronic devices are tiny, and so are the ports that connect them to the outside world. A fine mesh-like membrane usually prevents particles and dust from entering and affecting the mic performance.
Why is how you speak into your mic important?
Photo by Muhammadtaha Ibrahim Ma’aji
Microphones on cellphones and headsets are tuned and optimized for human speech at an expected distance and volume level. Intuitively, when your phone is in handset mode, it expects you will hold the phone close to your face. When it’s in handsfree mode, it expects you to hold the device 25-30cm away from your face. If you bring the phone in closer than that or yell into the microphone, that isn’t going to make your voice clearer for the person at the other end, it will make it sound much worse.
If you’re using wired earbuds with a microphone element on the cable, the mic is generally intended to be resting on, or clipped onto your upper chest, and is tuned to work at that distance. Tempting as it may be, if you grab that little mic and hold it right in front of your mouth, the level will be too high and will cause clipping distortion and render your voice less intelligible for the person at the other end.
Many VOiP applications allow you to test and adjust your microphone (and speaker) levels outside of a call. Make use of this feature to ensure your mic level falls into the optimal range when you’re speaking normally.
The same applies to headsets that feature a boom microphone: don’t pull the mic too close to your mouth. While we’re on the subject of boom mics: these can be directional, meaning they will reject sound from one side and amplify sound from the other. Check yours to make sure it is orientated correctly with respect to your mouth.
How does signal processing help your voice?
Phones, tablets, and computer-based communications apps all include some form of signal processing to eliminate noise and echo from calls. Depending on your device, these can do a great job of making communication possible when you’re out and about, riding in cars, or waiting on the platform for your train. But if your call is really important, it’s best not to leave it to chance and find yourself a quiet environment that isn’t too reverberant (i.e., not a bathroom) and your voice will have the best chance of coming through clearly.
Why does Bluetooth only make your voice sound worse?
Bluetooth adds wireless convenience, but just like with music, it only makes your voice sound worse. That is simply because it adds a largely unnecessary detour to your voice’s journey. It means that the digital signal must pass through a Bluetooth codec, which also adds latency, then be transcoded by your device before resuming its journey and heading off on its way.
Even with perfect service and coverage, the way that audio is packed and sent over Bluetooth is another bottleneck that degrades audio quality and the overall experience. But if the network’s flaky, things can get much worse rapidly.
Why does network coverage impact call quality?
Once we’ve passed the microphone and its associated signal processing it’s time to consider your device’s service reception. No matter how good your phone’s microphone is, if you don’t have a strong radio signal, data transmission will be compromised. If you have a spotty network connection, then voice data is going to get dropped and the experience can get frustrating fast. If you’ve ever done a video call with a crappy Wi-Fi connection, you have a visual representation of what happens to your voice data over a bad connection.
Related: Why conference calls sound bad
How to fix your microphone problems
As we have seen, there are a number of factors that can contribute to poor microphone signal quality. If you experience issues with speech transmission, you should, first and foremost, make sure that nothing is seriously wrong with the microphone hardware. Once you’re sure there’s no grain of sand in there from last August, you can check the basic mic functionality by making a voice recording on your device. Isolate the issue further by taking any Bluetooth devices out of the equation. If Wi-Fi or cell signal strength is problematic, check your wireless router or check expected network coverage with your service provider.
We take mic quality seriously at SoundGuys, and have a dedicated microphone score for each product. Look out for that number when reading our product reviews.
Frequently Asked Questions
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