What is Lossless Audio? Everything You Need to Know about Lossless Audio
Listening to music used to be limited to people who had radios, to people who had gramophones and vinyl records, to tapes and cassette players, and then to CDs and finally, digital streaming.
Nowadays, most people pay for a streaming service, mainly to remove the advertisements and get the benefits of playing songs in the order which they want and other features which are generally available offline.
Offline music means either having physical media like CDs, or downloading music that is in some way compressed, leading to having multiple file formats, some of them producing lossy audio, some of them lossless.
What do lossy and lossless mean, though? Are they as important as they are advertised to be and does it matter for the average listener? Which file formats are lossless? Following are explanations of all of these terms, as well as a warning to have in mind.
What is Compression and What is Lossless Audio?
Digital audio can be distributed in a couple of ways but the most common one is compressed, lossy audio, due to the files being smaller at the cost of irreversible loss of audio quality compared to the original, uncompressed format.
This leads us to the three main types of digital audio, uncompressed, compressed lossless audio and compressed lossy audio.
Uncompressed Audio – Raw Music Files
Typically, uncompressed audio can be found on CDs, or in use by audio professionals, broadcasting services and enthusiasts. Uncompressed audio retains all the samples from the raw audio and some of it can be encoded in the LPCM or simply, PCM format. This implies a 44.100 Hz sample rate (recording the audio 44.100 times per second) and a bit depth of 16, meaning 16 bits per sample. 16 bits are used for each of the two channels an audio CD typically has.
Uncompressed audio is often stored in the LPCM format, but WAV is used on PCs (Windows and Linux computers) while Apple computers use AIFF. The problem with uncompressed audio is the file size, which can be up to 10 MB per minute or more, for a two-channel song. This is where compressed audio comes in, to help reduce the file size.
Compressed Audio – Not All Compression is Equal
Compression is necessary to reduce the file size of audio files, but some methods of compression irreversibly lose data, or rather, the ability to reconstruct the data accurately. Lossless and lossy compression are the two types used to compress raw audio recordings to reduce their sizes, but they have different use cases.
Lossy Compression or Irreversible Compression
Lossy compression is typically used for consumer applications such as smartphone listening or with MP3 players, named so after the audio format and compression method. Lossy compression eliminates some frequencies which the human ear cannot hear, like very high frequencies, as well as frequencies which are played at the same time as something really loud, making them obscure.
This reduces the file size but also permanently discards parts of the original recording.
NOTE: Lossy audio is often imperceptible to lossless audio to a casual listener, even through higher quality gear.Lossless Compression – Reduced File Sizes and Preserved Integrity
What is lossless audio, then? Lossless audio means compressing a raw audio file (PCM), thus reducing its size, but allowing the file to be decoded with no samples lost. Compared to lossy compression, lossless does not discard any data, allowing almost perfect reconstruction. The most popular lossless audio formats are FLAC, APE (monkey’s audio) and ALAC.
Understanding compression is essential to choosing the right type for your music listening experience, but knowing which file formats to choose is also important.
The Best Lossless Audio Format – Does it Exist?
Audio formats, just like any other format in computing, are created to serve different purposes. There are over 17 lossless formats, but only some of them are applicable in more than a single system.
FLAC – Free Lossless Audio Codec
As the name implies, FLAC is a free codec used to compress audio without losing any of the original audio source’s data. The format is playable on all popular systems, including Windows, iOS, macOS, Android and Linux systems. It is by far the most popular lossless format, one of the reasons being that it is free (and does a great job at lossless compression). FLAC can be played by most MP3 players.
APE – Monkey’s Audio
While technically free, Monkey’s Audio is not open source, making it a problem for legal redistribution. It allows for great, high-quality audio files, which do require more resources for decoding, putting stress on the device (with flagship smartphones often struggling). It is available on most systems, from Windows, Android and even macOS.
ALAC – Apple Lossless Audio Codec
This format was primarily made for Apple devices in 2004, but was decoded by a developer in 2005. Apple made it open source in 2011, which makes it available for every device. It is playable on Android, Apple systems, Windows and all Linux-based systems.
Compared to other formats, it is as fast as FLAC, but much faster than APE, when it comes to decoding, making it a popular choice for encoding audio files.
The best format is a subjective matter, but from a practical standpoint, the best lossless format would be the one you can play on your devices without having to resort to multiple installations of codecs and players.
Conclusion and Summary – Lossless Audio is Great But
One should consider whether having a higher file size is worth it, with their own audio listening equipment and hearing in mind. To enjoy high-fidelity audio, you would need a good source, for example a FLAC song. Listening to it from a smartphone and cheap headphones will not make a difference. Having expensive headphones which require a dedicated headphone amplifier might make a difference, but our hearing is also a limitation.
While great for audio professionals and enthusiasts, lossless audio can be a detriment (in terms of storage space) for the average listener with poor gear.
If Hi-Fi audio is a hobby one wishes to pursue, then lossless audio and particularly the formats mentioned above, provide a great balance of size and quality.