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Demystifying Voice Over File Formats: A Sound Engineer's Guide

Updated: Jan 31

As a seasoned audio engineer with 35 years in the industry, I've participated in more than a few

Voice Sessions over the years. I've also witnessed the evolution of Voice Over recording delivery from 1/4" Tape (Ampex 456 of course) and Landline to DAT/CD and ISDN to Digital Pidgeon and Source Connect.

Just as choosing the right tape was important all those years ago, the right file format is just as crucial these days for ensuring the highest quality in your voice recordings.

The problem is, there are so many types out there, how do you know which is right for you, or the job you're working on? Let's delve into the essentials.

Common Voice-Over File Formats:

  1. WAV (Waveform Audio File Format):

  • High-quality, uncompressed format.

  • Ideal for preserving the integrity of voice recordings.

  1. MP3 (MPEG Audio Layer III):

  • Compressed format, suitable for smaller file sizes.

  • Widely used for online distribution.

  • Mp3 is not broadcast quality due to its compressed state. Therefore I wouldn't deliver Radio or TVC reads as an mp3 unless explicitly instructed.

  1. AIFF (Audio Interchange File Format):

  • Similar to WAV, often preferred in Mac environments.

  • Uncompressed, maintaining audio fidelity.

Decoding Sample Rate and Bit Rate:

  • Sample Rate:

  • Represents the number of samples of audio carried per second.

  • Common rates are 44.1 kHz (CD quality) and 48 kHz (standard for video).

  • Bit Rate:

  • Denotes the number of bits processed per unit of time.

  • Higher bit rates result in better audio quality but larger file sizes.

Unraveling 32-Bit Float:

The latest player on the audio field is 32 bit float. While it sounds like a great cocktail at your favourite club, it's actually a pretty neat bit of formatting.

In short, 32-bit float provides an expansive dynamic range, allowing for recording both extremely soft and loud sounds without losing details or introducing distortion. This is crucial in voice acting, where nuanced performances and varied intensity are common. You may like to use this if you are recording Voice for Gaming, Commercials with some loder shouting parts of softer whispering parts along with normal dialogue. Anywhere the dynamic range of your recording is going to be extreme. Outside of these types of scenario 24 bit will be more than adequate...

Choosing the Right File Type:

Consider your Distribution Platform:

  • WAV or AIFF for broadcast or high-quality productions.

  • MP3 for online platforms where smaller file sizes are crucial

Client Preferences:

  • Consult with your clients to determine their preferred file format.

  • Some clients may have specific requirements for sample and bit rates based on their workflow.

Balance Quality and File Size:

  • Strive for the best quality while considering practicalities like upload/download times.

In conclusion, the choice of file format, sample rate, and bit rate is pivotal in delivering top-notch Voice-over recordings. Understanding these elements empowers audio engineers and voice-over artists to collaborate seamlessly, ensuring that the final product meets the highest standards of excellence. Your sound is your signature – make it resonate with clarity and precision.

Ready to create your next voice demo.? Robbo is a seasoned audio engineer with 35 years of experience recording voiceovers for radio and advertising clients from around the globe. Find out more here...

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