AU to SOU Converter

Turn your AU recordings into SOU format online

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Advanced Options

Configure codec, sample rate, bit depth, and channel count to tailor the AU to SOU conversion to your exact needs.

Swift Turnaround

Converting AU to SOU takes only moments. The optimized pipeline ensures minimal wait time for your audio output.

Platform Independent

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

How to convert AU to SOU

1

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

2

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

3

Let the file convert and you can download your sou 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
SOU is a raw audio format designation that functions as an alias for unsigned 8-bit PCM data (u8) in the SoX audio processing framework. Files with the .sou extension contain headerless, uncompressed audio samples stored as unsigned 8-bit integers — each byte represents a single amplitude value from 0 to 255, with 128 as the silence midpoint. Because there is no header, playback parameters such as sample rate and channel count must be specified externally. The default assumption is typically mono at 8000 Hz, though the data can represent any rate the recording hardware supported. The u8 encoding that SOU aliases is one of the simplest possible digital audio representations, predating structured audio containers like WAV and AIFF. Raw unsigned PCM was commonly produced by early sound cards and digitizers in the late 1980s and early 1990s, when storage constraints and limited processing power made headerless formats a practical choice. One advantage is absolute simplicity: SOU files can be read by any program capable of basic file I/O, with no parsing of container structures or metadata decoding required — useful for embedded systems, hardware diagnostics, and educational contexts where audio fundamentals are being explored. The format's minimal overhead also means that conversion to any modern container is lossless and instantaneous, since the raw PCM samples can be wrapped in a WAV or AIFF header without any transcoding.
Developer: SoX Contributors
Initial release: 1991

Frequently Asked Questions

Why convert AU to SOU?

AU is a legacy UNIX format with limited software support today. Converting to SOU ensures broader playback compatibility.

What programs can open SOU?

Use SBStudio II, SoX, legacy Sound Blaster tools to play or edit SOU recordings. These tools offer reliable compatibility with the format.

Will I lose audio quality in the conversion?

Quality depends on the codec. If SOU uses lossy encoding, minor data loss occurs. Lossless targets preserve the original AU audio faithfully.

Can I convert several AU recordings at once?

Yes — upload multiple AU files simultaneously and convert them all to SOU in a single batch. No need to process one at a time.

What happens to my files after conversion?

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

AU to SOU Quality Rating

3.0 (1 votes)
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