AU to VOX Converter

Quick AU to VOX audio format conversion online

Drop files here. 1 GB maximum file size or Sign Up
to
Facebook Amazon Microsoft Tesla Nestle Walmart L'Oreal

Accurate Output

Expect reliable, high-fidelity results converting AU to VOX. The engine respects your original audio quality throughout.

Platform Independent

Access the AU to VOX conversion tool from any device with a web browser — no platform restrictions or downloads needed.

No Installation

The AU to VOX converter runs entirely in your web browser. No plugins, no downloads, no setup — just open and go.

How to convert AU to VOX

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose vox or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your vox file right afterwards

About formats

AU is an audio file format introduced by Sun Microsystems for its Unix workstations and the NeXT platform. It features a minimal 24-byte header specifying data offset, size, encoding type, sample rate, and channel count, followed by the audio payload. AU supports numerous encodings, including uncompressed linear PCM at various bit depths, mu-law and A-law companding (logarithmic compression used in telephone systems), and several ADPCM variants. This versatility made AU a workhorse across early Unix environments, web audio (Java applets defaulted to AU), and telephony applications. One advantage is simplicity: the compact header and straightforward structure make it trivial to parse, generate, and stream programmatically. The built-in mu-law option provides another benefit, delivering reasonable voice quality at just 8 KB per second — half the rate of 16-bit uncompressed audio — invaluable when storage and bandwidth were scarce. Although modern formats have largely supplanted AU in consumer applications, it retains a foothold in scientific computing and audio processing pipelines where minimal overhead and reliable cross-platform behavior are valued.
Developer: Sun Microsystems
Initial release: 1992
VOX is a headerless audio format built around Dialogic ADPCM encoding, widely adopted in telephony, interactive voice response (IVR) systems, and voice mail platforms since the 1980s. Each audio sample is compressed into 4 bits using an algorithm developed by Oki Electric and implemented in hardware on Dialogic Corporation's telephony interface cards. VOX files typically use a sampling rate of 6000 or 8000 Hz, producing extremely compact recordings optimized for speech intelligibility rather than musical fidelity. Because the format carries no header, playback software must know the sample rate and encoding parameters in advance — a trade-off that reduces overhead but demands careful file management. The primary advantage of VOX is storage efficiency: a one-minute voice recording at 8 kHz occupies roughly 240 KB, making it practical for systems storing thousands of prompts. Dialogic ADPCM conforms to the ITU-T G.726 standard, ensuring interoperability across telephony equipment from different vendors. Even as modern call centers migrate to IP-based systems with codecs like Opus), vast libraries of VOX recordings persist in legacy IVR deployments and compliance archives worldwide.
Initial release: 1983

Frequently Asked Questions

Why convert AU to VOX?

AU files are tied to UNIX and Java ecosystems. Converting to VOX makes your audio accessible on any platform.

What programs can open VOX?

Open VOX with Dialogic systems, SoX, Goldwave, telephony software. These applications provide full playback and editing support for the format.

How is audio fidelity handled during conversion?

The converter preserves maximum fidelity. If VOX is lossless, no data is discarded. Lossy codecs apply minimal perceptible compression.

Does the converter support batch AU conversion?

Absolutely. You can upload a batch of AU files and convert them all to VOX together, saving significant time on large collections.

What happens to my files after conversion?

Your original AU is deleted as soon as conversion ends. The resulting VOX is available for download and automatically removed within 24 hours.

AU to VOX Quality Rating

4.0 (2 votes)
You need to convert and download at least 1 file to provide feedback!