They are 'lossless' as opposed to 'lossy'. They include the popular FLAC (Free Lossless Audio Codec) and ALAC (Apple Lossless Audio Codec) formats, both of which are compressed but in a way that means that, in theory, no information is lost. That's not all: there are also several different hi-res audio file formats to choose from, all of which have their own compatibility requirements. 50 of the best hi-fi albums for audiophiles.And streaming technologies, like MQA (see below), have found a way to help tackle that. Thankfully, storage is much cheaper than it used to be, so it's easier to get higher-capacity devices. A hi-res file can typically be tens of megabytes in size, and a few tracks can quickly eat up the storage on your device or be cumbersome to stream over your wi-fi or mobile network. Hi-res audio does come with a downside, though: file size. You can also have 88.2kHz and 176.4kHz files too. Hi-res audio files usually use a sampling frequency of 96kHz or 192kHz at 24bit. The more bits there are, the more accurately the signal can be measured in the first instance, so going from 16-bit to 24-bit can deliver a noticeable leap in quality. Sampling frequency (or sample rate) refers to the number of times samples of the signal are taken per second during the analogue-to-digital conversion process. In its simplest terms, hi-res audio tends to refer to music files that have a higher sampling frequency and/or bit depth than CD, which is specified at 16-bit/44.1kHz.
In 2014, the Digital Entertainment Group, Consumer Electronics Association and The Recording Academy, together with record labels, formally defined high-resolution audio as “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". Unlike high-definition video, there’s no single universal standard for hi-res audio. Sony Walkman (Image credit: Sony) What is high-resolution audio?