Don’t know your aiff from your elbow? And what the fudge is a µ-law? Here’s a handy guide on what audio file type to request next time you’re booking a voice over.
For broadcast commercials in the traditional sense—TV and radio ads. And cinema ads. This is generally uncompressed, CD quality, big ass files.
- sampling rates: 48kHz or 44.1kHz
- bit depth: 16 bit
- channels: mono.
For telephone system voice overs—IVR and on hold messages. It sounds like you’re in a bucket. I die a little inside whenever I playback these files. The lower quality is cause phone systems used to be analog. It’s also a bit of a trade off between quality and bandwidth.
The specs are way low:
- sampling rate: 8kHz
- bit depth: 8 bit
- channels: mono.
Another one for telephone systems. Pretty much specific to telephone systems in fact. They so fancy. Actually pronounced ‘my-oo law’. Go figure. Generally specs are the same as the shit wav. You can go up to 16kHz for your sampling. Sounds marginally better than the wav. But still shit.
Explainer videos, social media ads, eLearning, audiobooks, podcasts, apps, long ass recordings. Generally stuff that’s pumped out over the internet. Or requires someone to download it and / or save to their device. Doesn’t sound as good as a wav cause lossy compression yo, but quality is on par with what you hear on the radio. And hello small file sizes. In fact, I have radio producers who request mp3s cause it’s easy to send over email and will be compressed to the max in the end anyways.
Specs are usually:
- bit rate: 128kbps (192kbps for audiobooks)
- channels: mono
This guide is based on common formats I’m asked to supply. It’s always worth checking broadcast, channel or platform specs first.