How to Fix High-Pitched Microphone Noise and Feedback

Nobody enjoys that ear-splitting screech from a microphone, and if you’ve ever been on stage when it happens, you know the feeling of wanting to disappear. Before you can fix it, you need to understand what’s actually going on.

That dreadful screeching is technically called feedback. Feedback happens when a microphone picks up sound from the speakers and re-amplifies it, creating a loop that spirals into an unpleasant squeal.

Beyond being annoying, it can genuinely damage your ears and blow out your sound system if it runs on too long.

How to Fix High Pitch Noises Coming From a Microphone

Put microphones and loudspeakers in the same room and feedback becomes a real possibility. We’ve already covered what triggers it, so let’s get into how to eliminate the high pitch noise coming from a microphone for good.

1. Place your microphone properly

Microphone Placement

Microphone placement is the single biggest factor in stopping feedback before it starts. You’ve got to know how and where to place your mic in relation to the speakers, so here’s how to get it right.

The Microphone Position in Relation to Loudspeakers

First rule: set up the mic so the loudspeakers aren’t firing straight into it. Ideally, position your microphone behind the loudspeakers and point it away from them.

Never aim a microphone at the speakers. Most mics pick up sound from the front and reject sound from the back, so always keep the front of the mic pointed at the actual sound source.

The Distance Between the Microphones and Loudspeakers

Get the microphone as far from the loudspeakers as you can while still keeping it close to the sound source. The farther the mic sits from the loudspeakers, the lower your odds of getting feedback.

The Microphone Position in Relation to the Sound Source

Get the mic right up close to the sound source. If you’re speaking into a handheld, don’t hold it a foot away from your mouth like a stopwatch.

The closer the mic is to the source, the cleaner the output. It won’t grab as much of the surrounding noise, which also kills off feedback before it can build.

2. Hold Your Microphone Properly

Whoever’s holding the handheld mic plays a massive role in whether feedback happens at all. In my experience, most feedback at live events comes from presenters or performers who were never taught how to hold a microphone correctly.

So what are the proper techniques for holding a microphone? To capture your voice cleanly while rejecting other sources (and shut down feedback in the process), a presenter or performer should know these techniques:

• Understanding the type of microphones and how they work
• Holding the microphone securely and close to the sound source
• Pointing the microphone away from the monitors
• Using directional microphones
• Avoid cupping the microphones
• Movements on stage
• Adjustments during soundcheck

Hold the Microphone Securely and Close to the Sound Source

Keeping the mic close to your mouth means it grabs more of the sound you want and less of everything else. A firm grip with all your fingers also keeps the mic from jostling around, since extra handling noise can get amplified into feedback.

When the mic captures a direct, clean signal, it pulls in less surrounding noise, the loudspeakers push out less excess sound, and your chances of feedback drop fast.

Point the Microphone Away From Monitors

Monitors sit on stage aimed at the performers so they can hear themselves during a live show. Most microphone polar patterns are designed to capture sound from the front and reject what’s behind, so the geometry matters.

Brief your presenters in advance: never point the front of the mic at a stage monitor. If anything, the tail end of the mic should face the monitor, unless you want a wave of feedback to crash down on your audience.

Using Directional Microphones

As mentioned earlier, directional microphones are the most convenient for use on a live stage because they only pick up sound from what they are pointed at.

On the contrary, omnidirectional microphones are prone to feedback since they capture sound from all angles and directions.

So, directional microphones are the best for anyone speaking into a mic because they increase the amount of gain before feedback.

Avoid Cupping the Microphone

Rappers and some vocalists think it looks cool to wrap their hand around the microphone capsule, covering the grille. It’s a habit that produces a muddy, honky sound and often triggers feedback.

When you cover the holes in the grille with your hand, you effectively turn a directional mic into an omnidirectional one that picks up sound from every angle. If you’re serious about killing feedback, tell your performers to stop cupping the mic.

It’s one of the worst handling habits on stage.

Movements on Stage

A handheld microphone comes with the freedom to move around on stage.

So, how will movements on stage influence your microphone sound?

To reduce microphone feedback as you move around:

• Always remember to keep the microphone pointed at and closer to your lips
• Avoid going near loudspeakers and monitors or being in a position where the speakers and monitors point at the top of your microphone
• You don’t have to move around. You can put your microphone on a stand to minimize movements on stage all together

3. Check the Placement of the Loudspeakers

Another big lever for killing that high-pitched noise is positioning your loudspeakers the right way.

Place Your Loudspeakers Forward

Keep your loudspeakers well away from the microphone and closer to the audience. Placing them forward increases the distance from your mic and cuts the chance that sound from the speakers will loop back into it.

As a bonus, when the speakers are closer to the audience, they get a clearer sound that’s coming straight at them.

Point Your Loudspeakers Away From the Microphones

Just keeping the loudspeakers away from the microphone isn’t enough. You also have to aim them correctly.

They should never face the microphone directly, but point in the opposite direction instead, which also keeps the sound from reflecting back toward your mic.

Point Your Loudspeakers Away From Reflective Surfaces

Avoid aiming loudspeakers directly at reflective surfaces and walls to cut the amount of sound that bounces back to the microphone.

Instead, point your speakers towards the audience so that the sound is clear and clean.

Also, you can use carpets and soft fabric such as curtains in space to prevent sound from reflecting on surfaces.

4. Check the Type of the Microphone

Knowing your mic types and how each one works makes a real difference here. For cutting high-pitched noise and suppressing feedback, reach for cardioid and super-cardioid microphones.

A supercardioid microphone tightens the pickup pattern even more, which does wonders for feedback rejection.

These patterns are more directional, so you get better isolation and strong feedback resistance because they’re built to reject sound from off-axis. Omnidirectional mics are the opposite problem.

They can’t cancel background noise and are notorious for triggering monitor feedback loops.

5. Check the Microphone’s Input

Let’s see how microphone input does not increase the risk of feedback.

Don’t Turn up the Volume

Most people crank up the microphone volume instead of just moving the mic closer to their mouth. That approach sends more sound out of the loudspeakers, which the mic then picks up all over again.

So keep the volume no higher than you actually need, and hold the mic close to your mouth.

Turn Down the Volume

One of the most effective and quick fixes to feedback is to find the microphone that is causing it and turn down the volume from the audio mixer immediately. Knowing how microphone gain works helps you find that sweet spot where the signal is strong but feedback stays at bay.

Simply put, turn down the volume of the offending microphone.

6. Check the Loudspeakers’ Output

Lower the volume of the loudspeakers to the level that is needed to prevent the microphone from picking up sound and thereby creating a feedback loop.

Again, make sure to place speakers closer to the audience than to the sound source.

7. Check the Number of Open Microphones

The more open microphones you’ve got running, the higher your feedback risk climbs. Fix this by limiting how many mics are live and muting anything you’re not actively using at that moment.

With fewer mics running, you get cleaner output and better overall sound quality. You’ll also have a much easier time tracking down the offender when feedback does kick in.

Reduce Microphone Sound Competition

For instance, in a live band, other musical instruments might be playing too loud that the sound from the microphone is inaudible.

This technique might not necessarily reduce feedback but it will help prevent turning up the volume of the microphones.

Consider putting the microphones farther from other musical instruments so they pick up less sound from them.

8. Equalize the Sound

Sound operators call this “ringing out” the room, which is the process of finding the resonant frequencies that feed back and cutting them with EQ.

Feedback shows up at different frequencies depending on how loud the microphone is running. Run a few soundchecks, listen for the offending frequency, and filter it out of the mix.

To eliminate microphone feedback by sound system equalization, you can use either of the following 3 types of equalizers:

• Graphic EQ
• Parametric EQ
• Automatic feedback reducers

Graphic EQ

A graphic equalizer is an easy and quick way to remove frequencies that cause feedback.

This process simply involves slowly turning up the volume of the microphones on a stage until you begin hearing feedback.

Ring out the room by detecting the offending frequency and cut it.

Parametric EQ

Parametric equalizers are more complex and capable of making precise sound adjustments than graphic equalizers.

This method involves sweeping a boost across a range of frequencies to find the offending frequency and then cut it to cancel out the feedback.

Automatic Feedback Reducers

Automatic feedback reducers are tools that reduce the risk of feedback occurring by automatically adjusting the equalizers.

These tools use a microprocessor that detects and automatically reduces the offending frequencies before feedback even occurs.

Automatic feedback reducers work effectively if your microphones are handheld, wireless, or if you have many open microphones on stage.

They are convenient if your ears are not trained to detect an offending frequency quickly or if you don’t want to keep on checking for offending frequencies.

9. Check the Type of Monitors

Swap your loudspeaker monitors for in-ear monitors or headsets so you can hear yourself while you play, speak, or sing without a speaker blaring onstage.

Taking loudspeaker monitors off the stage and away from your microphones slashes feedback risk in a big way. In-ears are pricier than traditional wedges, but if you can swing the budget, they’re worth every penny.

10. Beware of Room Acoustics

Room acoustics is just how sound behaves in an enclosed space. Every room, and every object inside it, reacts to sound waves differently.

This one’s largely out of your hands because it comes down to wherever you’re using the microphones. Even after ticking every other box, sound from your loudspeakers can still bounce off a reflective surface and find its way back into the mic, triggering feedback.

So how do you tell if your space has decent acoustics?

These factors play a crucial role in shaping the acoustic profile of a given space:

• The size of the room
• The shape of the room
• The materials used in the construction of the room
• The height of the ceiling
• Reflective or absorptive paneling
• The choice and positioning of furniture

How to Treat Room Acoustics

The acoustics of a given space can either make or break an experience.

In a room, sound waves are either absorbed or reflected by the surfaces, structures, and materials in that room.

To minimize the occurrence of feedback in a given room, you need to increase the surfaces that absorb sound waves and reduce the reflective surfaces.

Soft porous surfaces such as carpets, fabric curtains, furniture, and panels absorb sound waves while flat, smooth surfaces such as walls, tables made of glass, and large windows reflect sound waves.

Some of the fast and easy fixes to improving the acoustics in your room is to add things like carpets, fabric curtains, upholstered furniture, specialized acoustic panels to reduce sound reflection.

You can also incorporate automatic feedback reducers into your system to quickly detect offending frequencies and control possible feedback before it gets out of control.

Adjustments During Soundcheck

During soundcheck, the sound system is adjusted to make sure it is producing clear sound and that the volume level will not result in feedback in the actual live show.

It is also at this point that presenters/performers are taught the proper microphone handling techniques to ensure a smooth live show.

Quick Fixes to Feedback During a Live Event

Say you’ve done everything above to prevent microphone feedback, but that awful screech still breaks out mid-show. It happens.

Most feedback loops come from loud stage volume, bad microphone placement, or poorly positioned monitors and loudspeakers. Here are the quick fixes to stop that annoying noise the moment it starts.

3 Quick Fixes to Microphone Feedback

These are:

• Turn down the microphone
• Move the microphone
• Equalize the microphone

Turn Down the Microphone

Hands down, this is the fastest and easiest fix for microphone feedback, especially if you’re the sound tech. Identify the offending mic channel and pull the fader down.

If the stage monitors are the culprit, you just need to nudge down the volume on the appropriate monitor channels. A small adjustment can make a massive difference in overall sound quality.

Move the Microphone

This is another quick fix for microphone feedback.

If you find out that the issue is the position of the microphones in relation to loudspeakers and monitors, easily correct this by moving the microphones away from the speakers.

Sometimes, the microphones placed on stands can be too far from the presenter’s mouth.

Quickly fix this by moving the mics up, closer to the mouth to provide better signals.

Equalize the Microphone

Equalization comes in if you can’t turn down the volume or move the microphones.

This process is easy if your ears are able to catch the frequency creating the feedback fast.

As a sound technician, you need to be alert always to catch feedback and correct it fast while an event is happening.

To Recap How to Fix High Pitch Noises Coming From a Microphone

Technically, feedback is a sound loop between an audio input and an audio output, in our case, a microphone and loudspeakers.

It’s caused by:

• Improper microphone and loudspeaker placement
• Loud volumes from the microphones and speakers
• Using omnidirectional microphones
• Improper microphone holding techniques by presenters
• The acoustics of an enclosed space

How To Prevent Feedback?

• Properly position microphones and loudspeakers
• Adjust the volume of microphones and speakers during soundcheck
• Use cardioid and super-cardioid types of microphones
• Train presenters on proper microphone handling techniques
• Treat the acoustics of a room

How To Fix Feedback Quickly in a Live Session

• Turn down the microphone
• Move the microphone
• Equalize the microphone

The Causal Factors of Microphone Feedback

We now know what feedback or high pitch noise is, but what really causes this?

Here are the causal factors of microphone feedback:

• The microphone is at the wrong angle in relation to the loudspeakers
• The microphone and loudspeakers are in proximity
• The microphone is far from the source of sound but close to the loudspeakers
• Wrong positioning of the loudspeakers that point directly at reflective surfaces
• The increased volume of the loudspeakers
• The increased volume of the microphone
• The number of open microphones is unlimited
• The microphone is on when not in use
• Use of speaker monitors
• Omnidirectional microphones
• The size and shape of the physical space

Frequently Asked Questions

Why does my microphone make a high-pitched noise only at certain volumes?

Feedback occurs at specific frequencies depending on the volume and the acoustic properties of the room. As you increase the volume, different frequencies reach the threshold where the sound loop between the mic and speakers sustains itself, creating that high-pitched screech.

Can a feedback suppressor completely eliminate high-pitch microphone noise?

Automatic feedback suppressors can significantly reduce feedback by detecting and cutting offending frequencies in real time. However, they work best as a safety net alongside proper mic placement and volume management.

They are not a substitute for good sound setup practices.

Does using in-ear monitors instead of stage monitors prevent feedback?

Yes, switching to in-ear monitors is one of the most effective ways to prevent feedback. Since the sound goes directly into your ears instead of being projected through loudspeakers on stage, there is no opportunity for the microphone to pick up and re-amplify the monitor signal.

Final Thoughts

Microphone feedback is stressful for everyone involved, whether you’re in the audience, holding the mic, or running the board. Thankfully, that ear-piercing screech is completely fixable, and in most cases you can stop it from happening in the first place.

Put the tips in this article into practice and you’ll find that eliminating microphone feedback becomes quick and routine. Hopefully this guide helped demystify what causes feedback, how to prevent it, and how to shut it down fast when it sneaks through.