Somewhere in digital music history, audio at 44.1kHz 16bit became the accepted standard for CD. Our stock music library uses this standard (as do most) and all consumer music still uses it in 2019. However, it is an old standard now.
It is believed that these sample/bit rates were established from a balance between two factors, the minimum sample rate needed for the human ear and the amount of storage available on a CD. Obviously, at the time (1980s ) there would have been limits on what technology could achieve.
The human ear can hear up to a range of 20kHz in theory, however, in reality, it is probably somewhere between 15-18kHz. So, having the rate over double was deemed sufficient for quality. This is also to do with the Nyquist Theorem (or sampling theorem), which I will not cover here as it is technical and beyond the scope of this post.
At this sample rate, a CD was able to hold 74 minutes of audio.
It is said to have been devised by SONY and Philips.
But, why are we still using it 30+ years later?
It appears to have stuck for two main reasons:
- It is deemed good enough by most
- It has been so widely used on the CD format
Is it good enough though?
This is a contentious issue. There are passionate people who will tell you that higher resolution audio is much better and there are those who will tell you that the human ear can not distinguish the difference.
There are numerous cases on the web of people saying that they have tested it and can hear a difference, and just as many who say they can’t hear a difference. The problem is that it is subjective and the results rely on many variables, such as the speakers used, the quality of the Digital to Analogue conversion, how the source audio was recorded, the listening environment, the age of the person listening and the condition of their ears.
Regardless of which way you fall in this debate, or what you believe, there are higher resolution audio formats used in DVD and Blu-ray. Also, broadcasters broadcast in 48kHz.
- CD – 44.1 kHz at 16 bit
- Broadcast – 48 kHz at 24 bit (or 16 bit)
- DVD – 48 kHz at 16 bit
- Blu-ray – 96 kHz at 24 bit
It seems that regardless of common beliefs, companies are putting resources into developing higher quality audio formats. It is just that they are being used in film and TV, rather than as a music-only format.
Despite these higher formats used in other media, the standard for music is still 44.1 kHz at 16bit. This is probably due to the popularity of the CD (compact disc) format. It has now migrated into digital downloads too, albeit lower-quality compressed mp3 versions (which is another topic altogether).
Where does this leave music producers?
Often confused. To add to the mix, our DAWs (Digital Audio Workstations) typically have the capability to export audio at 44.1kHz, 48kHz, 96kHz or 192kHz with bit rates of 16. 24, 32 or 64.
The paradox is that the samples and virtual instruments are usually only recorded at 44.1kHz or 48kHz at 16 or 24 bit.
This means that any audio we export at higher resolution is upsampled.
My view is that 44.1kHz 16bit is okay, but I also have 48kHz 24bit versions of my music too. I think I can hear/feel a difference, but I have no proof. Furthermore, I could be tricking myself.
- With music, we are stuck on “CD quality” (44.4kHz 16bit) because of the popularity of the (now declining) CD format.
- With film and broadcast, we are using higher-resolution audio.
- People who create music have the means to make higher resolution audio, but the samples they use are recorded in lower resolution.
- Music is better (or not) in higher resolution depending on your point of view/listening experience.
It seems that music will be 44.1kHz at 16bit for the foreseeable future, but film audio has moved beyond that. Personally, given that music consumption is mostly streamed these days, I can’t see a reason to increase the quality for listeners as the audio is reduced in quality for streaming anyway. Furthermore, unless we are all able to have perfect listening environments and deal with massive audio file sizes it will not be beneficial.
For film, there is clearly a requirement for higher resolution audio. However, I must say we have never been asked for anything higher than 44.1kHz 16bit (which is the format we use in our royalty-free music library).
To make producing higher resolution music meaningful though, our samples really need to be higher resolution too. Otherwise, our DAW’s are just upsampling.
It does seem that most of the music used in Blu-ray film production is just upsampled too, as it is customary for a composer to deliver it in 44.1 or 48kHz, 16 or 24bit. Having said that, I do know of some cases where 96kHz delivery was requested.
I am going away to unknot my brain now, but feel free to share or comment if you have a view or experience in this matter 🙂