Why Do Microphones Screech? And How To Fix It

Screeching effect from microphones is called audio feedback.

Such screeching sound from microphones sounds very disturbing, and it spoils the whole rhythm.

Has it ever occurred to you that you were singing or speaking in a microphone, and all of a sudden a loud screeching noise came out of the microphone?

This is exactly what audio feedback is.

The simplest reason for audio feedback is that sound which leaves the microphone comes back to it forming a loop. 

This loop of sound causes the screeching noise.

Some rock music creators use this effect in their songs. 

But it doesn’t sound good when you are singing a pop song or when you are just addressing an audience.

Here, you will find the exact reason why do microphones screech and how to fix it. 

Why Does Screeching Occur?

As mentioned above, screeching is the result of a loop of sound.

But how does it happen?

When you speak into the microphone, the sound goes into the microphone.

The microphone feeds the sound signals to a mixer or some other sound system.

After that, your voice is amplified and sent to a speaker.

Normally you hear the amplified voice but under certain circumstances, the amplified voice goes back to the microphone and the process is repeated.

This is how screeching of microphones occur.

Reason For Screeching

Now that you understand how screeching occurs and the technical background of it, you must also know some reasons for the audio feedback.

Audio feedback occurs because your microphone might be too close to the speaker.

In this case, the microphone considers the sound coming out of the speaker to be the main sound and ignores your sound considering it a background noise.

The microphone ignored your sound because it has less amplitude than the sound produced by the speaker. 

How To Fix The Screeching?

If you ever happen to face the screeching or audio feedback by a microphone, you must stop it.

For this purpose, you have to break up the loop of the sound.

There are many ways of doing it, let’s find how to fix it. 

Keep The Speakers Away

I also mentioned above that if your speakers are too close to the microphone, the microphone will screech.

If your microphone starts screeching, take the speakers away from their position and place them far apart from the microphones.

The ideal position of the speakers is closer to the audience, facing the audience and far from you and the microphone.

It is always better when the speakers are not facing the microphone. 

Turn The Microphone Off

If you happen to produce screeching noise from the microphone, the quickest solution to stop it is to turn the microphone off.

When you turn the microphone off, it will not pick up the sound from the speaker.

Hence, the sound loop will be broken. 

Moreover, you can avoid screeching by turning the microphone off when you are not using it.

It often happens that people throw their microphones on the floor after a performance without switching the microphone off.

Mostly when the microphones are wired, people throw them near to the speaker so that the wire doesn’t break with tension.

At that time, when the microphone is thrown on the floor, it produces a sound which is picked up by it. 

The microphone does its job, and the output produced from the speaker is fed to the microphone again.

It leads to the production of sound loop.

That’s why you notice screeching at the end of a performance often. 

Speak Closer To The Microphone 

When you are speaking or singing, be sure to be close enough to the microphone.

This will help you avoid screeching because the microphone will consider your voice to be the main one. 

Directional Microphone 

It is better to use a directional microphone that picks up sound from a certain microphone if you want to avoid screeching.

The directional microphone will pick up the sound only from one direction, so you can be in that direction.

This way, only your sound will be picked up by the microphone. 

Be Aware Of Reflective Surfaces

When you aim the speakers to a reflective surface such as a wall, the sound isn’t absorbed and it comes back to the microphone.

This way, the loop of sound develops and screeching occurs.

Use Soft Furniture

If you want to avoid screeching, use soft furniture and soft stuff such as carpets, sofas, curtains etc so that such stuff can absorb the sound.

This way less sound will be reflected to the microphone and the chances of screeching will also be less. 

Reduce Speaker Output

If you are in a room or if you don’t need too loud noise from the speakers, you can reduce it’s output.

By reducing the speaker output, less sound will be available to the microphones to screech.

The microphone will consider your sound only and not the sound produced by the speakers. 

Use A Good Quality Microphone

If you are facing the screeching even after taking all the precautions, it’s probably time to change your microphone.

Sometimes when microphones become too old, they start picking up sound from everywhere.

Microphones usually have a built-in system of cancelling unnecessary noises.

It might be possible that such a system has stopped working in your microphone. 

Buy a new microphone that has a cardioid polar pattern.

Such a system helps the microphone to pick up only the necessary noise. 

Conclusion

Screeching sound isn’t always bad because you can use it if you are composing a rock song.

Microphone screeching can be avoided by breaking the loop through which the audio feedback occurs.

You can also use a better quality microphone to get the least amount of screeching.

But no matter how expensive a microphone is, if you don’t take the above mentioned precautions, it can lead to screeching. 

Screeching from microphones doesn’t leave a good impact on the audience.

So, if you don’t want to annoy your audience, try to avoid screeching.

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