Microphones and the human voice

This is a well written article about the human voice, and how microphones really work in terms of capturing it. Even if you read this and plan to forget everything—you’ll come out *way* ahead when recording your and your guests’ voices.


It’s full of insightful information, about the human voice:

…the voice chances spectrum in almost any other position than when we approach the speaking person with our ear – or microphone. Each position on the head or the chest has its’ own sound color – or timbre. For instance, the spectrum of speech recorded on the chest of a person normally lacks frequencies in the important range of 2-4 kHz. This results in reduced speech intelligibility. If the microphone does not compensate for this you should make corrections with an equalizer.

Important frequencies:

The important frequencies in non-tonal (Western) languages are illustrated by the diagram below. Here, the frequency band around 2 kHz is the most important frequency range regarding perceived intelligibility. Most consonants are found in this frequency band.

…and about what affects intelligibility in a reproduction of the voice:

A lot of research has been carried out in this area. In general, the results demonstrate that:

1. Optimum speech level is constant when background noise level is lower than 40 dB(A)
2. Optimum speech level appears to be the level that maintains around 15 dB(A) of S/N ratio when the background noise level is more than 40 dB(A)
3. Listening difficulty increases as speech level increases under the condition where S/N ratio is good enough to keep intelligibility near perfect

Furthermore, the 1-4 kHz frequency range should be “kept clear”. When, for instance, adding music as background for narration, a parametric equalizer cutting the music 5-10 dB in this frequency range will improve intelligibility.


Listening to comprehend

When you’re in a job interview, a podcast interview, a sales call, a meeting… if we take the approach that this is a test and there’s a right answer, we’re not actually engaging and moving things forward.

~ Seth Godin, from https://seths.blog/2018/08/ignore-the-questions/

In a podcast conversation, if a guest slips into this-is-a-test mode, things get awkward. If I ask, “what’s something people get wrong about you,” the guest will think I’m looking for dirt, and that I want something they’d not want to share. Or worse, they wonder if I already know something, and that I want to drag that skeleton from their closet.

But the sort of conversations I’m interested in sharing are ones where those involved are working together to create something interesting, and which are respectful of the subject. So it’s important to create the environment where the guest naturally treats questions as prompts. It turns out that this is easy to do.

If I honestly want the good sort of conversations, then my actions follow automatically. I share things about myself and doing so invites the other person to share. I take things seriously which conveys that I value the interaction and what I’m hearing. I express my interest directly by asking interesting questions; questions which show the other person I’m generally curious. Overall, I demonstrate that I’m listening because I’m interested, rather than because I want to do something with what I’m about to hear.

I’m listening to comprehend; not listening to respond.


Performing with a safety net

When recording conversations for the Movers Mindset podcast the guests know I’m not going to edit what they say to change their meaning. They know I’m bringing journalistic integrity to the conversation. (I’m not doing strict journalism, but that feature of journalism is present.) I do my best to set up the correct space (physical, emotional and mental,) so that we can co-create the best conversation possible. I’m not digging for dirt, creating tension, nor trying to create any other saccharine artifice. But that doesn’t change the fact that we are performing for an audience. The final necessary piece to facilitating a great conversation is a safety net.

Each conversation… each performance is better if we can reach just a bit farther than we might normally be comfortable doing. That’s why I bring a safety net. I very clearly give the guest a safe word which they can incant at any time to take back what they’ve said.

I don’t include the guest in the post-production process. They’re not invited to review the material, or to give additional thoughts about what to keep or what to cut. In fact, the only people who have time to do that, are wanna-be cooks, who will only mess up the soup if I let them in my kitchen. Instead, I and my team do all the post-production difficult work which is in fact our responsibility. The guest already did the really hard work of being themselves on-mic.

I do also say, “take your time— silence is free and we can easily trim out 30 seconds of you thinking before you speak.” I’ve also a few other little coaching tidbits I share to prep them for being recorded. But it’s the safety net which makes them feel comfortable trying something they might otherwise hesitate about. Part of the magic of a great conversation is how it develops organically, and without the safety net most people dial their caution up a few notches to be safe. With a safety net, most people are delighted to take a leap to see what they can do.


Some thoughts on file organization

Within the team that creates the Movers Mindset podcast, we assign numbers to our projects. We use “R42” for our 42nd recording project, then R43, and so on. This enables us to start naming things from day one, in a way that we don’t have to change later. If you’re putting your files in a folder, what would you name it, that you could be sure wouldn’t change?

We also use our podcast’s initials on file names, “MM.” When we see files whose name contains, MM-R42… we know what it belongs too. It’s part of the Recording-42 project for Movers Mindset.

We also exclusively use people’s family names on files. So a raw WAV file from an interview is 20200423-MM-SMITH-TR1.wav … April 23, 2020 recording for Movers Mindset, of someone named “Smith”, and this is track one [a recording from one microphone.] 20200423-MM-SMITH-TR2.wav is track two, and so on. No matter where you toss that file, it’s going to make sense.

Eventually, a recording project might lead to one (or more!) episodes of our podcast. They get assigned episode numbers, EP56, EP57, etc. Then we have filenames like MM-EP57… and it’s always clear what that is.

Sometimes we have a dozen files to keep track of in a podcast episode and we end up with
MM-EP56-INTRO.wav (introduction recorded after interview)
MM-EP56-OUTRO.wav (outro recorded in post production)
MM-GCORD.wav (a little music ‘button’ used when joining bits of interview)
…the final episode is then MM-EP56-SMITH.mp3

Since I’ve typed this much, here’s another thing we do: We use consistently numbered folders to store the files. Every project has a folder, 2020.04.23 Bob Smith R42/EP56 — we create 2020.04.23 Bob Smith R42 in our archives when we do the raw recording, and at the very end we add the /EP56 to make it easier to find things. In side each project we create five folders 1 assets, 2 recording, 3 episode, 4 publication, and 5 social — the leading number ensure they sort in nice order in various displays. 1 contains anything the guest gives us (photos, writing) or any photos we take during recording. 2 is the raw original recordings, 3 is everything to make a podcast episode (intro, outro, whatever we have to assemble, AND the finished MP3), 4 is anything we create as part of publishing the episode (transcript, articles, highlights ) and 5 is anything that’s ok for social media and sharing. And then we have a multi-terabyte file server with a “few” files on it:


Equipment matters

I have a confession to make: even though I love sound, I don’t really like sound equipment. […] Unfortunately, my bad attitude clashes with an important truth about audio storytelling: your equipment matters.

~ Andrew Wardlaw from, https://transom.org/2020/recording-kit-tune-up/

Today, more of a bookmarking post than deep thinking. If you do anything with recording interviews—or even if you just own ONE cable to charge your phone—this article is chock-full of neat ideas.

…of course, if you’re into recording, I recommend handing your cash/cards over to someone you trust before reading it. I confess I was off on a few sites hovering over the buy button on a few new toys. ;)


Mono versus stereo

As people get started in podcasting, the question soon comes up: Mono versus stereo?

For the Movers Mindset podcast, we produce our content as mono, and not because we don’t care about audio quality—rather, because I don’t feel stereo gains me anything. Here’s a bunch of things to consider:

But first, an aside: Newb mistake with voices: Don’t put one voice in one channel, and the other voice in the other channel. This isn’t “stereo”, it’s simply a mistake.

Data file size: Stereo is roughly twice the size as mono. Two channels of data versus one, so double the size. Size directly affects download time, storage size on listeners’ devices, their cellular data usage, and relates to my personal disdain for data-size bloat on the Internet in general; all of which cause me to take that “twice the size” very seriously. If the file is going to be twice as big, I want it to be twice as good—or at least drastically better. Stereo isn’t, and so this alone is enough for me to pick mono.

Monaural listening: Many people only put one ear bud in, and some people only have one ear.

Mostly voices: The Movers Mindset podcast is mostly people talking. In fact, it’s mostly just two people talking… often just one person at a time. That single sound source is picked up by one microphone. The other voice, in one other microphone. So here again, publishing stereo gets me no improvement in the final product.

Music: is usually generated by a collection of instruments and voices and that performance does have a three-dimensional aspect. And that’s why we see music in stereo… but we also see lots of “surround sound” systems that do a much better job than a simple left-right channel setup. Meanwhile, the Movers Mindset podcast doesn’t have any music at all, so this doesn’t even factor into our decision. (We use just simple cords, played on a single guitar, recorded—you guessed it—with a single microphone. So even our “music” is already in mono.)

Immersion: If I wanted to really go all-in, to record what it really sounds like—what would it sound like if I was literally sat there—you need to use binaural recording. This involves using two microphones positioned literally like the human eardrums are. This requires either using expensive microphones that you wear in your ears, or using microphones which are built inside a mannequin head. Because it turns out that the presence of your head and bone conduction all affect how things sound to us.


Intentional complications

In search of escalation, McPhee complicated the formula. If the standard profile focuses on one subject, why not, he thought, try to profile two subjects who shared some peripheral connections? That is, go from A to A + B.

~ Steven Pressfield from, https://www.calnewport.com/blog/2011/11/16/complicate-the-formula-john-mcphees-deliberate-practice-strategy/

Also, a “complication” has an interesting meaning in the world of mechanical clocks.

I complicate things quite often. I clearly see the value in pursuing complexity; it requires increased skill and attention to detail. But—and you saw this coming, right?—every complication is an invitation to dive into a rabbit-hole.

The challenge for me is two-fold. First, to always keep the number of simultaneous rabbit-hole dives restricted. Rabbit-holes seem to multiple, well, like rabbits! One, two, or three at the absolute most, is all I can truly pay deep attention to. This is hard for me to stick to. Second, to learn to exit when the passion has subsided. By definition, (my definition that is,) a rabbit-hole is a non-esssential journey. Each of the journeys improves my life and some number of them are essential, but no one rabbit-hole in particular is essential. I must always remember to exit when I’m no longer interested.

To wit: Recording 60-seconds of practice (in the context of podcasting) every day is supremely useful as it enables exploring complications. There are countless opportunities to explore with each 60-second recording session. I fell madly in lust with the practice. I worked on a few different ideas, and made improvements. …and then the Spring romance subsided, and in a rare instance of following my second self-admonishment above, I walked away from the practice. …after not even two weeks! #winning


On podcasting

The short version of this story is simply: I’m simply curious. I try things. I make mistakes. I ask questions.

My podcasting journey began with the Movers Mindset project, which grew from conversations I started having as part of my personal journey rediscovering movement. Started in 2015, at first it was just a web site that shared others’ writing. But as I travelled, I kept finding myself in cool conversations until one day someone said, “you should have recorded that. I’d listen to that podcast.” Excited, but with no clue how much work it would be, I kicked off the Movers Mindset podcast at the start of 2017. For the first dozen episodes I did far too much of the work myself, until I wised up and started finding a few incredible people to share my new passion.

By this point I was devouring anything I could about interviewing. I smashed through thousands of podcast episodes in the process of wondering, “how does everyone else do it?” Podcasts, books, online courses… Everywhere I turned I found something new to work on in my own journey.

In the fall of 2018 I had about 30 interviews published on the podcast. I was getting comfortable travelling by plane, train and automobile, being invited into people’s lives to capture the Movers Mindset interviews. I was invited to the North American Art of Retreat, a Parkour leadership retreat, in the Cascade mountains outside of Seattle. There I did a series of interviews with the event’s presenters and organizers, and handed those recordings off for Art of Retreat to create their own podcast.

When 2019 rolled around, on a whim, I jumped into an Akimbo course called The Podcast Fellowship. I wanted to search for unknown-unknowns, to rethink everything I had done so far, and much about the Movers Mindset podcast changed in this period. To my surprise, I was invited back to be part of a small group of alumni who assist the coaches for the 4th, (and then the 5th, and 6th) running of the course. It’s mind-bogglingly inspiring and energizing to hang out daily with hundreds of people who share your passion. I even tried to summarize the fun of it in The Journey.

Meanwhile, the Movers Mindset episode numbers kept climbing and I’ve been branching out to interview more challenging guests; challenging for me as I’m forced to converse and discuss topics I know less and less about, but which none the less intrigue me endlessly. In the fall of 2019, this time with help from some of the Movers Mindset team, I was invited back to Art of Retreat. There, we did a second series of interviews for Art of Retreat’s podcast. Today (circa 2020) I’ve done over 150 recorded interviews and conversations… and every time I find new things to explore and learn.

I have another fun podcast based on my ever-growing collection of quotes. You can search for “Little Box of Quotes” wherever you normally listen to podcasts, and the related posts here on my blog are tagged, as you might expect, Little Box of Quotes.