You certainly know your audio formats, namida!
On the other hand, formats like WAV, OGG etc are literally just made up of what could be considered the audio equivalent of pixels. For each second of audio, there's thousands of these "audio pixels"... I believe 44100 is the most common number these days
The sample rate tends to refer more to the "bandwidth" of the audio, i.e. the possible
range of sound in terms of volume, frequencies, etc.
44.1KHz, for instance, covers the entire range of normal human hearing. Higher sample rates generally don't mean much to most people's ears, although they are technically capable of reproducing more audio information. The
bit rate is closer in audio terms to being relatable to the number of pixels in an image, because this refers to how many "bits" of audio there are per second, whereas sample rate is more to do with exactly what information is stored
in those bits.
Interestingly, when it comes to bit rate, CD audio is still one of the highest quality commercially available audio formats. Most CDs are encoded with 44.1KHz 16bit PCM with a bitrate of 1,411kbps. Some are even higher resolution/bit rate - I have a Porcupine Tree album that's mixed in 5.1 and (apparently) has a "HD Audio" bitrate of 9,216kbps! The surround sound mix is gorgeous, of course, but in terms of general quality I honestly can't tell the difference between this version and the standard version.
Conversely, the majority of MP3, AAC and other mainstream digital audio files are no higher than 256kbps, although they generally use the same sample rate and bit depth (44.1KHz/16bit) as CD audio. (Incidentally, bit depth - as I understand it - refers to how "analog" the bits of digital information can be - the higher the bit depth, the closer the reproduction of the original sound. 16 bits is fine, 24 bits is slightly better but greatly increases the file size.)
Both low bit rates and low bit depths result in lo-fi sound; lower bit
depths tend to distort the sound and make it "fuzzy" or "glitchy" (basically, retro gaming sound
), whereas lower bit
rates result in that wierd "glassy" sound that makes the audio sound like it was recorded in a fish tank (this tends to happen when speaking to people over Zoom or FaceTime).
Generally speaking, 44.1KHz at 16bit/256kbps is a great middle-ground for file size and audio information that the average person can perceive as "good quality". Only audiophiles and sound engineers are likely to be able to tell the difference between 256kbps and 1,411kbps. To my ears, the latter sounds
ever so slightly clearer - and this is if I'm listening very intently in an otherwise very quiet place. It's no wonder 256 has become the standard, especially for streaming.
It's like the difference between looking at a 1200 x 800 image, and then the same image at 6,000 x 4,000. If you zoom both images so you're observing them in an area that's, say, 600 x 400, they will likely look virtually identical. The only reason you'd ever need the larger image is if you were displaying it on a very large screen - but even then, most people viewing the screen are likely to be far enough away from it that the experience they'd get is probably
still comparable to viewing the image at 1200 x 800 on a smaller screen.
How does this translate to audio? Well - it is true that the difference in bit rate does become more noticeable at higher volumes, which is why DJs and audiophiles prefer to use lossy formats for listening at louder volumes through better quality speakers. But even then, the music is likely to be so loud that any discernable differences in quality become essentially meaningless.
As a musician, I always export my music to 1,411kbps WAV so that the master file is lossless (standard industry practice), but ultimately convert it to 320kbps AAC for general use/distribution. 256kbps is fine, but I like having the extra 64kbps just in case
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