Always ask for WAV. Always. If someone delivers your Spanish voice over file only in MP3 and you didn't specifically request that, something went wrong somewhere in the process. This is the single most important technical detail most clients overlook, and it can cost you a reshoot or a degraded final product that nobody can quite explain.
WAV is the master, everything else is a copy
The WAV file is uncompressed audio. What I record in my studio is what you receive — every frequency, every subtle breath, every texture of the voice. When your editor works with WAV, they have full control. They can EQ, compress, normalize, and process without fighting artifacts that were baked in during delivery.
MP3, by contrast, is a lossy format. According to the Audio Engineering Society, MP3 compression discards approximately 90% of the original audio data to achieve smaller file sizes. That 90% includes harmonic information that your brain processes even when you can't consciously identify it. The voice sounds thinner. Less present. Your editor has less room to work.
And here's the thing most people don't realize: you can always create an MP3 from a WAV. You cannot do the reverse. The data is gone. So if I deliver WAV and you need MP3 for your website player, that's a 30-second conversion. If I deliver MP3 and your broadcast engineer needs WAV quality for a TV spot, you're calling me back for a re-delivery or living with compromised audio.
The specs that actually matter
When you request WAV, specify: 48kHz sample rate, 24-bit depth. This is broadcast standard. Some clients ask for 44.1kHz/16-bit, which is CD quality and perfectly fine for most web applications, but 48/24 gives your post-production team headroom they'll appreciate.
Mono or stereo? For voice over, mono. A single voice doesn't need stereo imaging — that's what your mixer handles when placing the voice in the final soundscape. Stereo voice over files just double your file size for no benefit. (I once had a client insist on stereo delivery because they thought mono sounded "old-fashioned" — the final mix was mono-summed anyway, which made the whole debate irrelevant.)
Bit rate for MP3 matters if that's your final delivery format. Never accept less than 192kbps for professional use. 320kbps is better. Anything below 128kbps and you're in podcast-recorded-on-a-phone territory.
When MP3 makes sense
I'm not anti-MP3. It has legitimate uses.
Internal review files before final approval — MP3 keeps your email from bouncing. Quick social media cuts where the platform will re-compress anyway — fine. Placeholder audio for rough edits while you wait for the final mix — acceptable. But these are temporary, internal uses. The moment something goes to broadcast, goes to a client, or goes into a final deliverable, you want the WAV sitting in your asset library.
Have you ever watched a national TV spot and felt like the voice sounded slightly off, slightly distant, even though you couldn't identify why? Compression artifacts accumulate through the production chain. Each conversion introduces degradation. Starting with WAV and converting only at the final step minimizes that damage.
AIFF, the forgotten format
AIFF is essentially the Mac equivalent of WAV — uncompressed, full quality, same specs. Some post-production houses prefer it. According to a 2023 survey by Production Hub, approximately 34% of broadcast facilities in the US still request AIFF as their primary delivery format, particularly those running legacy Pro Tools systems. If your editor works on Mac and specifically asks for AIFF, there's no quality difference from WAV. I deliver either based on preference.
The only reason WAV became the default is Windows market share during the formative years of digital audio. Technically, AIFF and WAV are siblings. Treat them identically.
What to specify in your brief
When you brief a Spanish voice over session, include the technical specs alongside the creative direction. This saves a round of emails and potential re-exports. Here's what to include:
Format: WAV (or AIFF if your team prefers). Sample rate: 48kHz. Bit depth: 24-bit. Channels: Mono. File naming convention: whatever your DAM system requires — I've seen everything from "ClientName_ProjectName_Language_Date_V1" to incomprehensible internal codes that only make sense to one person in your organization.
But ask for the WAV master even if you also need compressed versions. Any professional voice over artist with a real studio can export multiple formats from a single session in minutes. I routinely deliver a WAV master plus an MP3 review file plus whatever specific format the broadcast network requires, all from the same recording. The additional effort is trivial. The protection it gives you is significant.
The real cost of wrong formats
A Fortune 500 client once came to me after their previous vendor delivered Spanish voice over files for a nationwide campaign in 128kbps MP3 only. The broadcast network rejected them. The vendor had disappeared. The client needed re-recording within 24 hours to hit their air date.
That's an extreme case, but lesser versions happen constantly. Files that sound fine on laptop speakers reveal their compression when played through proper monitors. Editors who have to work around artifacts instead of with clean audio. Quality that's "good enough" instead of what you paid for.
Understanding the full Spanish voice over process includes knowing what to expect at delivery. A professional session produces a professional file. That file should be WAV, 48/24, mono, clearly named, and delivered alongside any compressed variants you specifically requested.
Streaming platforms have their own rules
Netflix, Amazon, Hulu — each has specific delivery requirements. Netflix, for example, requires PCM audio at 48kHz/24-bit in their final mix specifications. If you're producing content for these platforms, your audio format choices at the voice over stage affect everything downstream.
Ask your post-production team what the final delivery spec is before you start recording. Work backwards from there. If the platform requires specific loudness standards (Netflix targets -27 LKFS for dialog, for instance), that information should reach the voice over artist so they can deliver files with appropriate headroom.
One last thing about "broadcast quality"
Everyone claims broadcast quality. It's a meaningless phrase without specs attached. Broadcast quality in 1995 meant something different than broadcast quality in 2025. The phrase has become marketing rather than technical. When someone promises broadcast quality Spanish voice over delivery, ask them: what sample rate? What bit depth? What format?
If they can't answer, they're guessing. And you shouldn't have to guess about something this straightforward.
Need a Spanish voice over for your next project? Get in touch and I'll get back to you within the hour.
