Without gettin into the nitty-gritty of digital audio this blog is about the basic differences between WAV and MP3 files.
Digital technology has done wonders in how the world works; none, more so than with audio. I grew up listening to vinyl records, 8-track and cassette tapes; when the 'digital format' was introduced in the early '90s, the record companies were releasing remastered (digitized) music and I started hearing instruments/sounds that I've never heard before. I often asked if the music I'd been listening to for all that time was being re-recorded because of these changes- it wasn't. As the technology improved I learned (a little bit) about 'digital music'; and how much cleaner it was (compared to vinyl/tape). In the old days, when music was recorded some of the sounds (from some instruments) were lessened, or even phased out electronically, because of the recording process. The same applies to voice-overs, too; although there's not much that's trimmed away (as is with music).
The most common form of digital audio is a Waveform Audio File Format (WAVE, or more commonly, WAV); with the most common settings: 44.1khz, 128kpbs, 16 bit (stereo, for music; mono for voice-overs); anything less would not be deemed 'broadcast quality'. The problem with WAV files: Their size.
This 1:30 voice-over file (above) was an audition I recently recorded.
Clicking ‘Save As’ for this recording you’ll see the format is an uncompressed WAV file, 44.1khz, mono, 16 bit (standard). The ‘Estimated File Size’ is 7.59 meg in size…pretty big; in fact, you’d probably have some issues if you tried to email it.
By simply changing the format from WAV to MP3 (of this recording) you'll see a greatly reduced ‘Estimated File Size: 1.37 MB”. Much easier to email and it sounds the same as a WAV file; but why is that?
Remember those hearing tests you've taken where you're sitting in this room with headphones on and you have to press the button when you hear the tone? The human ear has a range of upper and lower tones and, depending on the 'health' of your hearing, you may hear sounds that others don't and vice-versa. When you convert a WAV file to MP3 you are trimming out most of the audio spectrum that the human ear cannot process, as well as some of the audio we can. You're also minimizing repeated data. The end result is a much smaller file that sounds almost as good as the original, in fact most non-trained ears cannot even tell there's been some loss in sound quality. The result is an MP3 file that's smaller (in size) and will work better on portable devices with limited storage space like flash drives, mp3 players, cell phones and tablets. This process is not limited to just music; voice-overs, sound bytes...basically any digital audio file would have the same result.
It's also important to remember that if you're converting an MP3 file to a WAV file...you will NOT regain the audio quality lost when it was converted from WAV to MP3. You'd need the original WAV file for that.
by Rich Brennan