Now the high-resolution audio (HRA) hit the mainstream, and more devices and services that support the audio format are released. So what is the high-resolution audio? And what audio formats are the High-Resolution? Here you can find the answer.
What is High-resolution Audio?
There’s no universal standard for high-resolution audio, which is also called high-res audio or HRA, though The Digital Entertainment Group (in conjunction with the Consumer Electronics Association and The Recording Academy) has published the following formal definition for the term:
High-res audio is: “Lossless audio that is capable of reproducing the full range of sound from recordings that have been mastered from better than CD quality music sources.”
Now, when music is digitised for downloading and streaming purposes, it is basically broken down into a series of audio snapshots (sort of like how several still frames make up a film), and our brains interpret all these snapshots together as continuous sound. The more snapshots taken, the more detail a digital music file will have.
We won’t get too scientific – but just know that sampling rate is the number of snapshots taken per second when analogue sound waves are converted into digital. There’s another aspect called bit depth. It’s the amplitude of the waveform at each sample point (8-bit has 256 levels for each sample; 16-bit has up to 65,536 levels).
So, to recap: high-res audio refers to audio files that have a higher sampling rate and more bit depth than a CD (and it is is generally best to have the highest combination possible). A CD has a sampling rate of 44.1kHz and a bit depth of 16-bit, while high-res files have a sampling rate typically ranging between 96kHz and 192kHz at 16- or 24-bit.
Now, let’s talk about bitrate. It refer to the number of bits – or the amount of data – that is processed over a certain amount of time. So, in audio, it means kilobits per second. An iTunes song has 256 kilobits of data stored in every second of a tune. Like sampling rates and bit depths, it’s better to have a higher bitrate. But if you download a high-res file with a high bitrate, it’ll naturally take up more space on your computer.
What are some high-res file formats?
There are several high-resolution audio file formats to choose from, all of which support the above sampling rates and bit-depths. They include FLAC (Free Lossless Audio Codec) and ALAC (Apple Lossless Audio Codec), both of which are compressed but in a way where (in theory) no information is lost.
Other formats include WAV, AIFF and DSD, the format used for Super Audio CDs. The relative merits of the formats can be argued, but most crucial will be compatibility with your particular products and system.