IMA to VOC Converter

Re-encode gaming and embedded IMA audio as VOC online

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Settings

The codec to encode the audio track. Codec "Without reencoding" copies the audio stream from the input file into output without re-encoding if possible.
Set the number of audio channels. This setting is most useful when downmixing channels (e.g., from 5.1 to stereo).
Set the sample rate of the audio. Music with a full spectrum (20 Hz — 20 kHz) requires values not lower than 44.1 kHz to achieve transparency. More info can be found on the wiki.

ima

IMA ADPCM (Adaptive Differential Pulse-Code Modulation) is a compact audio coding standard published by the Interactive Multimedia Association in 1992, addressing the need for a lightweight, royalty-free compression scheme suitable for early multimedia PCs and embedded devices. The algorithm encodes each sample as a 4-bit nibble representing the quantized difference from the previous sample, while an adaptive step-size table adjusts dynamically to track signal amplitude — delivering a fixed 4:1 compression ratio over 16-bit PCM. Decoding requires only an integer multiply-add per sample and a small lookup table, so even modest 1990s CPUs could decompress in real time without dedicated DSP. The format became deeply embedded in the multimedia landscape: Microsoft adopted it as a standard ACM codec for WAV files, game engines relied on it for sound effects, and telephony equipment used it for voice storage. Its advantages are enduring: predictable 4:1 size reduction simplifies buffer allocation in constrained environments, the decode path runs on 8-bit microcontrollers, and the open specification made IMA ADPCM one of the most broadly implemented audio codecs in computing history.
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voc

VOC (Creative Voice) is a digital audio container developed by Creative Technology and introduced alongside the original Sound Blaster card in 1989. It served as the native audio format for the Sound Blaster family during the DOS era, when Creative's hardware dominated PC audio. VOC files are block-based: each file consists of typed data blocks that can carry 8-bit unsigned PCM, 4-bit and 2.6-bit Creative ADPCM, 16-bit signed PCM, as well as A-law and mu-law encoded audio. This block structure also supports silence intervals, repeat loops, and marker points, giving game developers fine-grained control over sound playback. A notable advantage was hardware-level decoding — Sound Blaster cards could play VOC data directly via DMA transfer, freeing the CPU for other tasks in an era when processor cycles were precious. The format saw extensive use in DOS games from id Software, Sierra, and LucasArts. With the rise of Windows and the WAV format, VOC gradually fell out of mainstream use, yet it remains important for retro gaming preservation and for anyone working with vintage PC audio archives.
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Format Conversion

Bridge IMA and VOC formats with a single click. Move audio from gaming and embedded to mainstream compatibility.

Online Conversion

Encoding happens in the cloud — your device stays free while our servers handle the IMA to VOC conversion.

Superior Codec

Move from raw IMA to VOC — a format with better compression and broader support.

How to convert IMA to VOC

1

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

2

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

3

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

About formats

IMA ADPCM (Adaptive Differential Pulse-Code Modulation) is a compact audio coding standard published by the Interactive Multimedia Association in 1992, addressing the need for a lightweight, royalty-free compression scheme suitable for early multimedia PCs and embedded devices. The algorithm encodes each sample as a 4-bit nibble representing the quantized difference from the previous sample, while an adaptive step-size table adjusts dynamically to track signal amplitude — delivering a fixed 4:1 compression ratio over 16-bit PCM. Decoding requires only an integer multiply-add per sample and a small lookup table, so even modest 1990s CPUs could decompress in real time without dedicated DSP. The format became deeply embedded in the multimedia landscape: Microsoft adopted it as a standard ACM codec for WAV files, game engines relied on it for sound effects, and telephony equipment used it for voice storage. Its advantages are enduring: predictable 4:1 size reduction simplifies buffer allocation in constrained environments, the decode path runs on 8-bit microcontrollers, and the open specification made IMA ADPCM one of the most broadly implemented audio codecs in computing history.
Initial release: 1992
VOC (Creative Voice) is a digital audio container developed by Creative Technology and introduced alongside the original Sound Blaster card in 1989. It served as the native audio format for the Sound Blaster family during the DOS era, when Creative's hardware dominated PC audio. VOC files are block-based: each file consists of typed data blocks that can carry 8-bit unsigned PCM, 4-bit and 2.6-bit Creative ADPCM, 16-bit signed PCM, as well as A-law and mu-law encoded audio. This block structure also supports silence intervals, repeat loops, and marker points, giving game developers fine-grained control over sound playback. A notable advantage was hardware-level decoding — Sound Blaster cards could play VOC data directly via DMA transfer, freeing the CPU for other tasks in an era when processor cycles were precious. The format saw extensive use in DOS games from id Software, Sierra, and LucasArts. With the rise of Windows and the WAV format, VOC gradually fell out of mainstream use, yet it remains important for retro gaming preservation and for anyone working with vintage PC audio archives.
Initial release: 1989

Frequently Asked Questions

Why convert IMA to VOC?

IMA ADPCM is headerless and hard to use outside embedded systems. VOC provides a proper format with broad compatibility.

What applications open VOC files?

DOSBox, SOX, and retro computing emulators can handle VOC files. Most are available as free downloads for major operating systems.

How is the VOC audio quality?

VOC provides good quality at standard settings. The output clarity depends on the original IMA recording quality.

How fast is the conversion?

IMA files are typically compact. The conversion to VOC completes in just a few seconds on our cloud servers.

Are my files kept private?

Uploaded IMA files are deleted immediately after conversion. VOC results are automatically erased from our servers within 24 hours.