If streaming music is your jam, you might have heard that Apple is introducing its lossless ALAC format to Apple Music for all users. Apple, like other major music streaming services, is touting the benefits of lossless and high-resolution audio over conventional audio playback.
The industry-wide shift towards offering high-resolution and lossless audio options poses each of the following questions:
What is lossless audio? Is it the same as high-resolution? If not, then what’s the difference and why should we care?
Let’s examine these terms and see if there is anything to back the hype.
In the early days of music streaming, transferring music files over the internet was a hassle. The internet was still in its infancy, so the speed was low and the reliability questionable.
Back in the day, storage space was also quite expensive. So, music distributors had to figure out a way to distribute music using as few resources as possible. This is where lossy audio came into the picture.
When it comes to music, studio recordings are quite big in size. They can occupy tens of megabytes of storage space. In an era where most people didn’t have gigabytes of storage, delivering uncompressed studio recordings was not practical.
As a result, music productions created highly compressed audio files to dramatically reduce file sizes. These compressed files are the lossy audio files we know today.
While lossy files do save storage space, they sacrifice audio quality because they are highly compressed. Nevertheless, the industry adopted lossy audio files as the de-facto standard to deliver music to the listeners.
Lossy audio files are everywhere nowadays. From YouTube to Spotify, all streaming sites play compressed music. Fortunately, through the use of modern encoders and audio formats, these files sound good. So, most people don’t complain.
That said, the music we stream is not the same as the studio version. It is of lower quality. And a part of the reason because of the compression techniques that music productions apply on top of the original recordings.
Lossless audio files either do away with the compression completely or use compression techniques that don’t result in any data loss. So, if you are streaming lossless audio, you are streaming music that doesn’t have compression artifacts. This can potentially increase the audio quality.
However, lossless files do not always result in better-quality sound. If the compressed files are themselves of poor quality, removing compression won’t help much. So, take a test and see if lossless audio makes any noticeable difference.
What are Sampling Rate and Bit Depth?
Computers are digital machines that process 1s and 0s. So, any information that a computer needs to store—including audio—must be stored in the form of a string of 1s and 0s.
Sound, on the other hand, is not digital. It is analog and continuous in its nature. So, if we want to store sound on a storage drive in a computer, we have to convert it into 1s and 0s.
There are many ways to go about this conversion. One of the simplest is Pulse Code Modulation (PCM).
The following is the representation of Pulse Code Modulation.
In PCM, we take analog audio, play it, and sample it at a pre-determined rate in the form of 1s and 0s. This data is then stored in an audio format.
To understand the process better, imagine yourself taking pictures of kids playing baseball. If you were to take 30 pictures per second for an entire hour, you would have enough data to produce an hour’s worth of 30 frames per second video footage.
The same thing happens when you sample an audio signal. You are taking figurative snapshots of the audio signal, at a set rate. Encode all of these snapshots and you would have an audio file.
To play the audio file, your computer would just need to play the snapshots back at the same rate at which they were captured. This rate is called the Sampling Rate.
We measure the sampling rate in kHz. The standard sampling rate in audio CDs is 44.1kHz.
Now, because any audio is composed of more than one sound with varying frequencies, we need to store more than 1s or 0s to store all the necessary information. So, we need to aim for the biggest sample size possible, as the bigger the sample, the better the sound quality.
The sample size aka the number of bits in every sample is called the Bit Depth. The standard bit depth in audio CDs is 16-bit.
For all the hype music streaming services create about high-resolution audio, it is surprising that there is no standard definition. There is no agreement about what high-resolution audio really is.
That said, the consensus is that an audio sample having a high sampling rate and a high bit-depth is termed as high-resolution.
As you can see, the above definition is ever-changing. For instance, when 8-bit audio was the standard, 16-bit/44.1 kHz was high-resolution. And today when 16-bit/44.1 kHz is the standard, 24-bit/96 kHz lies in the high-resolution territory.
High-resolution audio, in theory, sounds crisper and better. It has more dynamic range, better instrument separation, and low noise.
The Difference Between Lossless and High-Resolution Audio
As we’ve explained above, lossless audio is the audio sample that doesn’t have any degradational compression on top of it. Such samples are in their original form.
So, lossless audio doesn’t mean higher quality audio. Any audio, whether high-resolution or not, can be lossless.
On the other hand, high-resolution audio is better quality audio that has a higher bit depth and a high sampling rate. High-resolution audio can be lossless or lossy.
High-Resolution Audio Formats
With the rise of high-resolution audio, streaming services have started introducing some proprietary audio formats. Some of the most well-known formats include FLAC, AIFF, WAV, and ALAC. All of these formats support high-res audio with a lossy or lossless compression.
For instance, Apple uses ALAC for high-res streaming on Apple Music. ALAC is a lossless format meaning its compression doesn’t degrade the sound quality. It is also incredibly space-efficient. If we compare it to WAV, which applies no compression, ALAC takes half as much storage space.
Similar to Apple, Tidal uses its own audio format called MQA. MQA has lossless compression and provides almost the same sound quality and storage space benefits as ALAC.
Lossless Is Not High-Resolution
Lossless audio is not the same as high-resolution audio. Where the former defines the effect of compression on the audio sample, the latter is the measure of fidelity of the audio. So, lossless audio can be low-res or high-res.
With Apple joining the pack, high-res audio has been catching on in recent times. As more and more streaming services start offering high-res music, it pays to invest in decent audio equipment.
So, invest in a decent pair of headphones, subscribe to a streaming service that offers high-res music, and enjoy.