U16 - Sound Formats

Sound format

Sound format is a file format for storing digital audio data on a computer system. Different sound formats are for different purposes. Some sound formats are more suitable for web distribution or uploading to a digital playlist and some are more suitable for music and studio production. Examples include WAV, AIFF, FLAC,  MP3,  AAC, WMA and Ogg Vorbis.

A WAV file is a lossless, uncompressed format and high quality, making it suitable for video and music production purposes. The advantages of  WAV file is that it is a lossless format, which allows the sound of the WAV file to be a close replica of the original audio. WAV files can easily be converted into other file types such as AIFF, AAC and MP3.  However, a WAV file will consume a big memory space.

An AIFF file is an Apple proprietary format and lossless. Similar to the wav format, it directly copies the original audio and maintains high quality sound. However, a AIFF file takes up a huge amount of space on your computer.

An MP3 file is the most common lossy format. Many store music on their phones as MP3 as it takes up a lot less space than a lossless file and its supported by a range of websites and devices. However, a lossy format means that the quality of sound is reduced by permanently taking away some elements.

A WMA is a file used with Windows Media Player. WMA stands for Windows Media Audio. WMA is both an audio format and an audio codec. An advantage of WMA is that is protecting the music copyrights and strongly preventing piracy by using DRM (Digital Rights Management) facility, which is embraced by musicians and music publishers. A disadvantage is that compatibility can be a huge issue because of less support from other platforms or various mainstream devices. 

Storage

Audio files can be stored on digital drives. It is important when producing your audio that you always have a backup copy of your work. When you are importing your audio files into any video software, the project file needs to be saved into the same folder as the raw audio. You can then create a back-up of this material on:

- Flash drive/USB: A Flash drive/USB is a common interface that enables communication between devices and a host controller such as a personal computer (PC). It connects peripheral devices such as digital cameras, mice, keyboards, printers, scanners, media devices, external hard drives and flash drives. An advantage of flash drives is that they are portable and can be used for multiple purposes. In addition to that, they are durable because they do not have moving parts. They are also very affordable and easy to use. However, If a flash drive is connected to a computer that is infected with malware, then it is at risk for also being infected, putting the data stored on the drive at risk of corruption or theft. Even worse, if the owner of a compromised flash drive is unaware of the exposure, then the flash drive can spread the malware to other devices to which it is connects.

- Hard drive: A Hard drive is a non-volatile hardware device that permanently stores and retrieves data on a computer. A hard drive allows you to store more as it has a higher storage capacity. This is handy if you are working with large files to keep space free on your PC or Mac. You can also use an external hard disk drive to backup your computer to protect your data in the event of a hard drive crash. However, hard disk drives don’t come password protected. If you misplace your drive, anyone can plug it in and access your data. An external drive limits your level of security. Keep your drive somewhere safe to avoid data theft.

- Cloud backup services: A Cloud drive is a web-based service that provides storage space on a remote server. An advantage is that stored files can be accessed from anywhere via Internet connection. Also, all cloud storage services reviewed in this topic have desktop folders for Mac’s and PC’s. This allows users to drag and drop files between the cloud storage and their local storage. However, there are concerns with the safety and privacy of important data stored remotely. The possibility of private data commingling with other organizations makes some businesses uneasy.

Compression

Compression is used to reduce file sizes and change various attributes of an image file. These attributes include file type, resolution, dimensions and bit depth. Types of compressions include:

- DRC: Dynamic range compression (DRC) is an audio signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds thus reducing or compressing an audio signal's dynamic range. This is good for reducing file size which means there is more space on your device however these loud sounds may be needed as it creates more of an effect.

- Downward compression: The vast majority of compressors apply 'downward compression' which means, in essence, that loud sounds are made quieter. More specifically, signals below the threshold level are left alone, while those above are 'squashed' by an amount determined by the ratio setting.

- Upward compression: This involves processing that squashes the quieter elements while leaving the loud bits alone. This means you will not be able to hear the quieter sounds which may be needed. However, this is better than downward compression which makes the loud sounds quieter and these loud sounds are needed in the sound file to create an effect.

Size versus quality

- Lossy: Lossy file compression results in lost data and quality from the original version. Lossy compression is typically associated with image files, such as JPEGs, but can also be used for audio files, like MP3s or AAC files. In audio files, the lossyness may produce a watery sound or reduce the dynamic range of the audio. An advantage of a lossy file is that because lossy compression removes data from the original file, the resulting file often takes up much less disk space than the original. However, lossy files reduce the data and quality of the original audio file.

- Lossless: every single bit of data that was originally in the file remains after the file is uncompressed. All of the information is completely restored. An advantage of a lossless file compression is that it maintains the quality from the original file.
On the other hand, lossy compression reduces a file by permanently eliminating certain information, especially redundant information. When the file is uncompressed, only a part of the original information is still there (although the user may not notice it).

- Bit rates: The bit rate of a file tells us how many bits of data are processed every second. Bit rates are usually measured in kilobits per second (kbps). Bit rates can affect file size, image quality, accessibility, and delivery cost. Therefore, you are able to change your file format depending on the bit rates if you would like to change the image quality etc.

- File size: A file size is the measure of space a file takes on a storage medium such as a computer hard drive. Therefore, you are able to identify how much storage the file takes up on your device.