Herman, we have a very practical, technical question on the table today, and it is something that actually hits quite close to home for us. Our housemate Daniel has been doing some digging into the backend of the podcast, looking at our file storage and the website, and he noticed something about our audio quality that has him questioning our choices. We are sitting here in our stone-walled apartment in Jerusalem, trying to make things sound as professional as possible, but Daniel is looking at the cold, hard data.
Herman Poppleberry, at your service. And yes, I saw that message from Daniel as well. He was looking at the Amazon S3 bucket where we store our episodes for myweirdprompts.com and noticed we are exporting everything at one hundred ninety-two kilobits per second. He pointed out that for a spoken-word podcast, that might be a bit of an overkill. He actually sent me a screenshot of the egress costs for the last month, and while we are not breaking the bank, he thinks we are being "data-gluttons."
It is a classic engineering trade-off, right? Quality versus file size. Daniel mentioned he had read that ninety-two kilobits per second might be plenty for voice, and he wanted to know when those high bit rates actually matter and when we are just wasting space. I think this is a great excuse for us to really dive into the weeds of digital audio compression. It is February two thousand twenty-six, and you would think storage is free by now, but when you are serving thousands of listeners, those kilobits add up.
I love it. It is one of those topics where people have very strong opinions, but often those opinions are based on how things worked twenty years ago rather than how they work today. To answer Daniel's question, we really have to define what bit rate actually represents in a digital audio file. Most people think of it as a "quality slider," but it is more like a "data budget."
Right. Most people hear bit rate and think quality, which is true in a broad sense, but technically, it is just a measure of data density. It is the number of bits that are processed per unit of time. So, if we are talking about one hundred ninety-two kilobits per second, that means every second of audio is represented by one hundred ninety-two thousand bits of data. If you have a thirty-minute episode, you can do the math—it starts to occupy a significant chunk of a megabyte very quickly.
Exactly. And the magic happens in the codec, like the MP3 codec Daniel mentioned. The job of that codec is to take a massive amount of raw audio data and figure out what it can throw away without the human ear noticing. This is called lossy compression. It relies on psychoacoustics, which is the study of how humans perceive sound. It is essentially the art of lying to the human brain so convincingly that the brain doesn't realize it is being cheated.
I find psychoacoustics fascinating because it is basically a way of hacking our biology. For example, if there is a very loud sound at one frequency, our ears literally cannot hear a quieter sound at a nearby frequency. This is called "simultaneous masking." The encoder knows this, so it just deletes the data for that quiet sound. Why keep it if the listener's brain is going to ignore it anyway?
Precisely. And then there is "temporal masking," where a loud sound hides quieter sounds that happen immediately before or after it. The bit rate is essentially the budget you give the encoder to describe what is left after all that masking. If you give it a high budget, like three hundred twenty kilobits per second, it can keep almost everything, including the subtle textures of the room. If you give it a tiny budget, like thirty-two kilobits per second, it has to start making some really tough decisions. It might start cutting out high frequencies entirely, which is why low-quality audio sounds "muffled," or it might introduce metallic-sounding artifacts because it just doesn't have enough bits to describe the complexity of the sound wave.
So let us address Daniel's specific point about our podcast. We are at one hundred ninety-two. He suggested ninety-two, though I suspect he might have meant ninety-six, which is a more standard increment in the world of audio engineering. Is ninety-six kilobits per second enough for a podcast like ours?
It is a bit of an "it depends" answer, but generally speaking, for a mono recording of just voices, ninety-six kilobits per second is actually quite good. In fact, many professional podcasts use sixty-four kilobits per second for mono. The catch—and this is the thing Daniel might have missed—is that we produce our show in stereo.
That is an important distinction. When you have a stereo file, that bit rate budget is split between the left and right channels. So, a one hundred ninety-two kilobits per second stereo file is essentially giving each ear ninety-six kilobits per second. If we dropped the whole file to ninety-six kilobits per second in stereo, each channel would only get forty-eight kilobits per second.
And that is where you start to notice it. At forty-eight kilobits per channel, the "S" sounds—the sibilance—start to sound a bit crunchy or swishy. You lose that crispness in the voice. It starts to sound like we are talking through a thin layer of aluminum foil. So, if Daniel wants us to save space, the move wouldn't necessarily be just dropping the bit rate; it would be switching the entire production to mono and then setting it to something like eighty or ninety-six kilobits per second.
But we like our stereo field, Herman. I like being in the left ear and you being in the right ear for our listeners. It creates that sense of being in the room with us here in Jerusalem. You can hear the slight reflection of the stone walls differently in each channel. If we went to mono, we would lose that "spatial" intimacy. So, if we stay in stereo, is one hundred ninety-two really the sweet spot, or could we go lower without losing that feeling?
We could definitely go lower. One hundred twenty-eight kilobits per second is the industry standard for a reason. It is the point where, for the vast majority of listeners using standard earbuds or car speakers, the audio is indistinguishable from the source. Going up to one hundred ninety-two is what I call the "safety margin." It ensures that even if someone is a real audiophile with high-end open-back headphones, they aren't going to hear any compression artifacts in the high frequencies.
It is interesting that Daniel mentioned his housemate experience because we are all living in the same house, but we all listen to things differently. I usually listen to podcasts on my phone speaker while I am doing dishes. In that scenario, I probably couldn't tell the difference between sixty-four and three hundred twenty. But Daniel is often at his desk with those massive studio monitors. He is hearing every single bit.
Exactly. But then you have the use case of something like transcription. Daniel mentioned he is doing a lot of speech-to-text work lately. When you are sending audio to an artificial intelligence engine for transcription, does bit rate matter then?
That is a great question. You would think the AI would want the highest quality possible, but most modern speech-to-text engines, like Whisper from OpenAI or the latest Google Gemini speech APIs, are actually trained on relatively low-fidelity data. They are designed to handle phone calls, which are notoriously low quality. In fact, most of these models downsample the audio to sixteen kilohertz the moment they receive it.
Phone calls are usually sampled at eight kilohertz and have a very low effective bit rate. So, for transcription, you can be incredibly aggressive with your compression. If you are recording a voice note just to have it transcribed, you could go as low as thirty-two kilobits per second mono and the accuracy of the transcription would likely be identical to a high-resolution file. The AI doesn't care about the "warmth" of your voice or the "air" in the room; it just needs the phonemes.
The only danger there is if you have a lot of background noise. If the bit rate is too low, the encoder might struggle to separate the voice from the hum of an air conditioner or the sound of traffic. It might turn all of that into a garbled mess that confuses the AI. So, for transcription, I usually recommend sixty-four kilobits per second mono as the "safe" floor. It gives the AI enough clarity to distinguish between a "P" and a "B" sound even in a noisy environment.
That makes sense. Now, what about the other end of the spectrum? Daniel asked about evidence capture or situations where you need a very high bit rate. This is where we move away from just "hearing the words" and move into "preserving the reality." This is where we talk about forensics.
Right. If you are a journalist or a legal professional and you are recording an interview that might be used in court, or if you are a field recordist capturing the sound of a rare bird in a forest, you don't want any lossy compression at all if you can avoid it. You want what we call lossless audio. Because once those bits are gone, they are gone forever. You can't "enhance" a low-bit-rate MP3 to find hidden details.
And that is a different world. That is where we talk about formats like Free Lossless Audio Codec, or FLAC, or just raw Wave files. In those cases, the bit rate isn't a fixed target like one hundred ninety-two; it is much higher. A standard CD-quality Wave file has a bit rate of one thousand four hundred eleven kilobits per second.
Compare that to our podcast at one hundred ninety-two. It is a massive difference in data. But the reason you want that for evidence or high-end production is for something called "headroom" for processing. If I take an MP3 and try to boost the volume or change the pitch, I am amplifying the errors and the missing data that the codec threw away. It is like trying to edit a photo that has already been through a heavy Instagram filter.
Right. It is like trying to zoom in on a low-resolution JPEG photo. It looks fine at original size, but the moment you try to manipulate it or blow it up, it falls apart into blocks. If you are capturing audio for evidence, you might need to filter out a specific background noise or enhance a whisper later on. You need every single bit of original data to do that effectively. In fact, in two thousand twenty-six, many field recorders are moving to thirty-two-bit float recording, which has an effectively infinite dynamic range. You can't even talk about bit rate in the same way there because it is more about the precision of the volume levels.
I also think about archiving. If we want this podcast to be around in fifty years, we should probably keep a high-resolution master file, even if the version we put on Spotify is a smaller MP3. Because who knows what kind of audio restoration tools will exist in the future? They will work much better on a high-bit-rate file. Imagine an AI in the year two thousand seventy-five trying to reconstruct our faces from the sound of our voices—it will want all the data it can get.
That is a very good point. Now, Daniel also asked for a general-purpose recommendation for an MP3 codec. If someone is just setting up a recorder for general voice notes or meetings, what is the "set it and forget it" number?
For me, if it is just voice and it is an MP3, one hundred twenty-eight kilobits per second mono is the perfect balance. It is small enough that you can store thousands of hours on a modern phone, but the quality is high enough that it sounds professional and is perfectly clear for both humans and AI. If you are recording a meeting with multiple people, one hundred twenty-eight mono ensures you can hear the person at the far end of the table without the compression "smearing" their voice.
I would agree, but I would add one technical nuance for the nerds out there: Variable Bit Rate versus Constant Bit Rate. We currently use Constant Bit Rate for our show because it is more compatible with some older podcast players and hosting platforms. But Variable Bit Rate, or VBR, is much more efficient.
Explain that, Herman. Why is Variable Bit Rate better?
Well, think about a podcast. There are moments when we are both talking and the audio is complex—maybe there is a car horn in the background or we are laughing. The encoder needs a lot of bits to describe that complexity. But then there are moments of silence, or moments where only one of us is making a very simple sound. A Constant Bit Rate file uses the same amount of data for that silence as it does for the complex speech. It is literally wasting bits on nothing.
Ah, so Variable Bit Rate acts like a smart budgeter. It says, "Oh, nothing is happening right now, I will only use eight kilobits for this second," and then when things get loud and complex, it jumps up to two hundred fifty-six kilobits.
Exactly. It averages out to a smaller file size with higher perceived quality. The only reason we don't use it for the podcast is that some very old web browsers or cheap MP3 players from ten years ago get confused by it and show the wrong duration for the episode. They might think a thirty-minute episode is only ten minutes long because they are calculating the total time based on the low bit rate at the beginning of the file. It is a legacy issue.
That is such a classic "tech debt" problem. We are using less efficient formats today to support devices that almost no one uses anymore. But for Daniel's personal voice notes or transcription files, Variable Bit Rate is absolutely the way to go. He should set his app to "VBR High" and never look back.
Definitely. And since he mentioned using an app like ASR on Android, most of those modern apps have a "High Quality" setting that usually defaults to something like one hundred twenty-eight or one hundred sixty kilobits per second. For voice notes, that is more than enough.
I want to go back to the idea of the "ninety-two kilobits" that Daniel mentioned. I suspect he might have been reading about the Opus codec. Have you looked into Opus lately, Herman? It seems to be taking over the world.
Oh, I am so glad you brought up Opus. If we really want to talk about the future of this podcast and audio in general, we have to talk about Opus. It is an open-source, royalty-free codec that is basically the king of efficiency right now. It was designed to replace both MP3 and the more advanced AAC.
It is what YouTube uses for its audio streams, right? And WhatsApp for those voice messages that everyone sends?
Yes, and Zoom, and Discord. The amazing thing about Opus is that it sounds better at sixty-four kilobits per second than an MP3 does at one hundred twenty-eight. It is incredibly efficient because it uses different encoding techniques for speech and music and can switch between them on the fly. If we were to switch our podcast feed to Opus at ninety-six kilobits per second, the files would be half the size and would actually sound better than what we have now.
So why aren't we doing that? Is it the same compatibility issue we have with Variable Bit Rate?
Exactly. While modern browsers and phones support it, the RSS feed ecosystem for podcasts is still very much stuck in the MP3 era. Apple Podcasts and some of the other big distributors expect an MP3 or an AAC file. If you give them an Opus file, it might just not play for half your audience. We are waiting for the industry to catch up to the technology.
It is frustrating, isn't it? We have the technology to make the internet faster and storage more efficient, but we are held back by the need for universal access. It reminds me of how long it took for everyone to stop using Internet Explorer. We are in two thousand twenty-six and we are still tethered to a format from the nineteen nineties.
It is the curse of the successful format. MP3 is so universal that it is hard to kill, even though it is technically inferior to almost everything that has come out in the last decade. But back to Daniel's question about when high bit rates actually make sense. There is one area we haven't touched on: music.
Right. We have been talking about the spoken word, where the frequency range is relatively narrow—mostly between eighty hertz and fifteen kilohertz. But music is a whole different beast. If you are listening to a full orchestral piece or a track with a lot of high-frequency percussion like cymbals, the bit rate becomes critical.
Absolutely. Cymbals are the ultimate test for an audio codec. They are essentially white noise, which is very hard for a compression algorithm to describe efficiently. At low bit rates, cymbals start to sound like "swishing" water or like they are being played through a metallic tube. This is called "aliasing." For music, I would never go below two hundred fifty-six kilobits per second if I am using MP3. Ideally, you want three hundred twenty.
And that is why services like Tidal or the "Lossless" tier of Apple Music are popular. Even if many people can't hear the difference in a blind test, there is a psychological comfort in knowing you are hearing exactly what the artist intended, without any bits being tossed in the trash. It is about the integrity of the art.
I think that psychological aspect is a huge part of the "high bit rate" culture. There is this term, "audiophile," which often gets associated with people spending thousands of dollars on gold-plated cables. But in the digital world, it just means people who want the highest bit rate possible. And while I respect the pursuit of quality, there is a point of diminishing returns.
I remember seeing a study where they took a group of professional audio engineers and had them compare a three hundred twenty kilobits per second MP3 to a lossless Wave file. Even the pros struggled to tell the difference consistently in a double-blind test. Our ears are amazing, but the compression algorithms have gotten even better. They are designed to exploit the very limits of human hearing.
They really have. Which brings us back to Daniel's observation. If we dropped our podcast from one hundred ninety-two to one hundred twenty-eight, we would save about thirty percent of our storage costs and bandwidth. Would our listeners notice? Probably not. Would it make the show worse? Technically, yes, by a fraction of a percent. But is that fraction worth the extra cost?
It is a funny thing to think about. We are sitting here in Jerusalem, recording this, and the data is flying across the world. Every kilobit we save is a little less energy used by a server somewhere. It is a small thing, but when you have millions of people downloading a file, those small things add up to a significant environmental impact.
That is the "green" argument for lower bit rates. Efficiency is a virtue. But I think for us, the "safety margin" is still worth it. We don't want someone listening on a high-end system five years from now to think, "Wow, those guys really sounded crunchy." We are building a library here, not just a temporary broadcast.
True. But I think for Daniel's use cases, he can definitely be more aggressive. If he is capturing evidence, stay high, stay lossless—use FLAC. If he is doing transcription or voice notes, he can drop that bit rate way down to sixty-four mono. It is all about the "intent" of the recording.
I think that is the key takeaway. You have to ask yourself: "What is the life cycle of this audio?" If it is a voice note that you will listen to once and then delete, thirty-two kilobits is fine. If it is a podcast you want to live forever, one hundred twenty-eight to one hundred ninety-two is the zone. If it is a historical record, go lossless.
I also want to mention the "sample rate" because people often confuse it with bit rate. Daniel didn't ask about it, but they go hand-in-hand. We record at forty-four point one kilohertz, which is the CD standard.
Right. The sample rate determines the frequency range you can capture. According to the Nyquist-Shannon sampling theorem, you need a sample rate that is double the highest frequency you want to capture. Since humans can't hear much above twenty kilohertz, forty-four point one kilohertz captures everything we can possibly perceive.
Some people record at ninety-six kilohertz or even higher, claiming it sounds "airier" or more "natural." What is your take on that, Herman? Is that just more bit rate waste?
For ninety-nine percent of people, yes. Unless you are planning to slow the audio down significantly—like for sound design in a movie where you want to turn a bird chirp into a monster growl without it becoming grainy—there is no reason to record at ninety-six kilohertz. It just doubles your file size for no audible benefit. It is like having a television that displays colors that the human eye literally cannot see. It is the "ultraviolet" of audio. It is there, but you aren't using it.
I think this is where the nerdiness really shines through. We want the "best," but the "best" is often just "more than we can use." It is like buying a car that can go three hundred miles per hour when the speed limit is sixty. It is cool to know it can do it, but you are never going to use that capacity in the real world.
Exactly. And for Daniel, who is looking at the bills, that extra capacity looks like a leak in the roof.
So, to summarize for Daniel and for everyone listening: if you are using an MP3 codec for general purposes, one hundred twenty-eight kilobits per second is your best friend. It is the "Goldilocks" zone. If you are doing mono voice notes, you can even go down to sixty-four. And if you are doing something that requires high fidelity or future-proofing, don't just increase the bit rate—switch to a lossless format like FLAC.
And if you are a developer or someone building a new app in two thousand twenty-six, please, for the love of all that is holy, use the Opus codec. Let us move the world toward a more efficient future. Let us stop paying for bits that no one can hear.
I wonder if we should actually try an experiment for our next episode. We could record it at a really low bit rate and see if anyone notices. Or maybe just one segment. We could do a "low-fi" segment where we drop down to eight kilobits per second just to show people what it sounds like.
Oh, the listeners would definitely notice if we went that low. We would start sounding like we were calling in from a submarine in the middle of the Atlantic. But it would be an interesting test of our "audiophile" audience. I bet we would get some very angry emails from people with expensive headphones.
We should probably stick to our one hundred ninety-two for now, just to keep Daniel on his toes. But I do appreciate him looking at the numbers. It is good to have someone keeping an eye on the "waste" in our system. It keeps us honest.
It really does. It is the classic housemate dynamic. One person is making the art, and the other person is wondering why the cloud storage bill is so high. It is a balance.
Exactly. Well, I think we have thoroughly explored the world of bit rates today. It is one of those things that seems simple on the surface but has so much interesting science underneath it. From psychoacoustics to the Nyquist theorem, it is all about how we interface with technology.
It really does. And before we wrap up, I just want to say that if you, the listener, found this deep dive into audio engineering interesting, we would really love it if you could leave us a review on your podcast app. Whether it is Spotify or Apple Podcasts, those ratings really help people find the show. And if you are listening on a high-end system, let us know if you can hear the Jerusalem stone in the background!
They really do. And it is always fun to see what people think of our "weird prompts." You can find everything we have ever done at myweirdprompts.com, including the RSS feed if you want to subscribe. We promise to keep the bit rate high enough that we don't sound like robots.
And if you want to send us a prompt like Daniel did, there is a contact form on the website. We are always looking for new rabbit holes to jump down, whether they are technical, philosophical, or just plain weird.
Definitely. Well, thanks for the technical breakdown, Herman. I feel like I understand our "data budget" a lot better now. I might even be able to win an argument with Daniel later.
My pleasure, Corn. It is always fun to geek out on the stuff that makes our show possible. Just tell Daniel that the extra bits are for "artistic texture."
I will try that. Alright, everyone, thanks for listening to My Weird Prompts. We will be back next time with another deep dive into whatever Daniel—or you—decide to send our way.
Until then, keep your bit rates high and your artifacts low.
Goodbye, everyone.
Bye-bye.
