How to actually fix “voice popping”​ in podcasts – since “anti pop screens”​ don’t actually work

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Podcasts are now a big thing: another opportunity to broadcast someone’s ideas and messages to thousands of people across the world – and how many can resist the idea of selling their ideas to millions of people?

Anyway,

very few who venture in this interesting realm know how to operate technologic devices. And end up having all sorts of quirks in their recordings – one of the most usual being “popping sounds” for certain consonants. Like “P” and “T”.

How to fix it

Do a very strong “P” sound with your mouth, and put your open hand front of it: you’re gonna feel the air moving. Move your palm until it’s just outside the air movement – that’s where you have to put your microphone.

Problem solved. Without pop screen nor any other sort of contraption.

As reference: here’s a picture of where good voice miking positions usually end up being.

Or, if you need a more visual reference, here’s our dear Joe showing you how it’s done:

And, in case you’d like to have a full tutorial on audio recording (e.g. Audio cards and stuff), here’s one from our website:

https://lmkprod.com/guide-how-make-studio-quality-voice-recordings-home/

Why people want to stick microphones in their mouths

Humans think visually. So, more or less: they’re naturally inclined to interpret phenomena in an immediately tangible visual way (nominally: “things go in line from A to B”) – within this case: “My voice comes out of my mouth. Hence, I must catch it from there: I’m gonna put the microphone exactly in front of it”. Which is wrong. I’m gonna show you a very rough sketch of this concept:

Voices are made by sounds – who, not quite intuitively, respond to radically different dynamics: acoustics. In which you have phenomena like radial propagation and resonance. Who are gonna syndicate how, for instance, you can absolutely put the microphone completely offset to your mouth – and still pick up 100% of the necessary signal. Because voice, thank God, propagates in a radial fashion (see picture above) – which is why you can speak to people even if they’re not standing directly in front of your mouth, with their head twisted on the side (surprise surprise: you might have not noticed, but “your microphones”, as in your ears, are not facing forwards: they’re on the side of your head – because, again, sounds propagate in a radial fashion. Hence, no need to stick your ears on your face. That’s a better suited position for light receptors – eyes).

Another case, of course, of how psychology is fundamental to understand human behaviours – even when in “scientific environment”.

Why the “Pop” happens

Inside microphones, there’s a tiny tiny sensor that captures all sounds. So to transform them into electric signal, and sent to your recording device.

Being this sensor very tiny (the mike might look big – but the real sensor itself, the infamous “capsule”, is super tiny: most of the microphone is just for handling and protection), a smack of air like the one coming from a loud P from your mouth is gonna hurt it too much – and give those stupid booming noises we’re all annoyingly acquainted too.

Another problem due to this, is vibrations – hence, the reason because we use decoupling systems, like “spiders”, to fix them (a spider cradle, with all its soft tangly wires, kills vibrations).

A microphone spider – for real LinkedIn doesn’t have “text align” function, and I have to write obligatorily on the left side???

Why “Pop screens” don’t actually work

The fabric with which they’re made is too thin to block the air pressure excess.

It’s so thin you can see through it – because, once again: our brain is biased to think “If I can’t see through it, it might block the sound“.

You could probably improve it using thicker fabric, like a (you might laugh, but it works) microfiber cloth – yeah: those cheap ones to dust off furniture. But, since you don’t even need it, why bother?

Why Mp3 is good, or: how I learned to stop worrying and love the lossy audio compression.

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Long story short: the Mp3 is perfectly fine for music listening – as long as you don’t abuse its compression.


Wanna know the scientific details about it? Keep reading.

The basics: the concept behind the Mp3 standard

Human senses far from the perfect system everybody seems to assume are.

First of all: they’re strongly limited by our brain’s capacity to interpret signals brought by our “sensors” – meaning that, although we might be receiving a given data, it is not assured that we will be able to elaborate it successfully. To be aware of it.
In this case: sounds captured by our ears.

And second: our “sensors”, for evolved they might be, are of organic nature – therefore: imperfect. Fragile. Prone to irreversible wear (aging, for example).

Mp3 based its concept upon these 2 factors: why record everything, when we’re able to perceive only a part of what we hear?

In other words: Mp3 used the studies upon human hearing limits in order to cut away everything we are not able to hear – not much differently than when, long time ago, the 44.1 Khz frequency become the golden standard for audio sampling (we can hear till 20Khz. And, due to Nyquist theorem, the right sampling frequency is at least the double of the one we need to record).

By the way: the “studies upon human hearing limits” is a science, and it is called psychoacustics – a wildly interesting argument, about which you can read more in this well crafted Wiki article: https://en.wikipedia.org/wiki/Psychoacoustics

At this point, we already have answered the question about why Mp3 is very good: the lost data is something we wouldn’t have heard anyway – therefore, although lost, it won’t impair audio quality.

The technical part: how Mp3 works

The Mp3 was created with a complete list of all of our “auditory system’s weaknesses”, in order to spot what we are likely to not to hear in an audio track.

The list is quite long and complex, and contains pretty interesting stuff like the auditory masking (about which you can read in this Wiki article: https://en.wikipedia.org/wiki/Auditory_masking). Who, in a very few words, is our inability to listen to two very similar sounds, both in frequency or time of happening.

Depending how hard we’d like to compress an audio track, the algorithm will erase more and more content. And, with very high compression rates, it will start erasing clearly audible data – although in a way that will optimize the most its loss.

The practical part: how to use Mp3 for music listening

First of all: the audio format is just a part of a longer “audio listening system” – in technical terms: an electroacoustic chain. All the elements involved in audio reproduction. Elements like cables, amplifiers, and speakers. And, long story short, with modern day’s excellent equipment, the only part of the electroacoustic chain who is still likely to ruin your listening experience is the final one: the speakers/headphones.

If you want professional quality, for high end listening purpose, 300KBPS is a good choice – although it’s something outside of 99,99999% Earth’s population possibilites: to hear music with this quality, you’re going to need a reference listening system (don’t know what it is? Read more about it here: https://lmkprod.com/guide-how-to-recognise-the-quality-of-an-audio-recording/ )

If you want maximum listening quality, for demanding genres like symphonic or Metal music, it is advisable to not go below 200KBPS.

If you need average listening quality, for less spectrally complex music (english for “music with quieter, less colorful instruments”) or casual listening situations (car, train, parties…), 150 KBPS is enough for your daily music listening.

The even more practical part: what’s better than Mp3

For cool it might be, Mp3 is still a lossy format: a little part of the auditory content will be irremediably lost – problem that we’ve solved with lossless algorithms. Nearly magical systems who, at the trade of higher CPU demand, will shrink your file with no quality loss.

I present you, dear reader, to the present and future of audio compression: the FLAC format.

FLAC compression format has quality level who matches an uncompressed format such as WAVE, but with a compression ratio up to 50% of its original size. Way bigger than the average Mp3, but with no quality loss whatsoever.

The price to pay for this? WAY more CPU demand. But not a big deal, with modern availability of calculation power.

Moral of the story: buy a good pair of headphones, and serenely listen to your nicely compressed (aka above 150 KBPS) Mp3s – unless you can get hands on FLAC files and players.