Which Audio File Type?
If you already have a digital recording mechanism which produces digital transcription files, there’s a good chance that it will record a variety of different file types for different purposes. This article aims to discuss these different types and suggest the right one for you, depending on your circumstances. If you are still considering which digital recording device to purchase then you have the opportunity to consider the file types it will produce before you buy.
If you do not know what file types you are working with, you can tell by looking at the file extension. This is the set of three letters that follow the dot, as in, for example, ‘interview.wav’.
The different file types all have advantages and disadvantages in their use, the most obvious of which is a trade-off between quality and file size. Sound files can be very, very large if they are not compressed, but compression is ‘lossy’ – in other words a complete or ‘lossless’ audio file has been taken and compressed, removing data that is considered redundant, which can result in reduced audio quality which may make it difficult for the person undertaking the digital transcription.
It may initially seem obvious that you want the ‘best’ quality but in fact,
many lossy formats have a negligible quality loss but are much smaller files.
If you are planning to email files to your VA, the advantage of a 2MB file,
as opposed to one 40MB in size should be obvious! No sound file of any length
is small, but at least it is possible to email a 2MB file. Most service providers
won’t allow a 50MB file through, and even if they did it could take hours to
download, blocking both your email and your VA’s. More and more VAs are using
a system which bypasses email; you can either upload files directly to their
website or send your files using a simple file transfer programme. However,
even these options have limits to the file sizes, as a rule.
It also worth noting that depending on the playback software your VA is using, they may only be able to play back certain file types. Some cover practically all digital file types while others are more limited, so it is worth checking first.
The ‘right’ file type and attributes for you will also depend on what the purpose of your recording is. If you are dictating a lower sound quality will still provide a clear enough recording for transcription. If you are recording a focus group, for example, where several people are talking, situated at different distances from the recorder and speaking at different levels and pitches, you will probably need a higher sound quality to accommodate this.
Your recording equipment may allow you to set different attributes for the same file type. This can make an enormous difference to the sound quality and size of the file. In some cases, for example dictation (one person speaking into machine, in a quiet environment) you can probably afford to loose sound quality and the recording will still be clear for transcription. In other cases (focus groups, noisy environments) you may find you need to choose a slightly larger file size in order to maintain decent sound quality).
Attributes are often shown as Hz. 8,000kHz mono is suitable for dictation and the range goes up to 44,100kHz stereo, which is the top quality, used for music CDs.