VOX to IMA Converter

Re-encode Dialogic VOX with IMA ADPCM compression

Choose Files

Drop files here. 1 GB maximum file size or Sign Up

ADPCM Bridge

Move between two 4-bit ADPCM variants — from Dialogic telephony to the IMA standard used in games and embedded systems.

Compact Output

IMA ADPCM at 4 bits per sample keeps your audio small. Similar compression to VOX in a more widely supported codec.

Web-Based

No SDK needed. Convert VOX to IMA directly in the browser.

How to convert VOX to IMA

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

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

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

About formats

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.

Developer: Dialogic Corporation

Initial release: 1983

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.

Developer: Interactive Multimedia Association

Initial release: 1992

Frequently Asked Questions

Why convert VOX to IMA?

IMA ADPCM is standard in games and embedded systems. Converting VOX adapts telephony audio for these platforms.

What can open IMA files?

SoX, Audacity, game engines, and Windows WAV support decode IMA ADPCM.

Both VOX and IMA use ADPCM — how do they differ?

VOX uses OKI/Dialogic ADPCM; IMA uses a different algorithm standardized by the Interactive Multimedia Association.

Is IMA better quality than VOX?

IMA ADPCM at 4 bits offers similar quality to VOX ADPCM. Both are 4-bit compressed voice.

Where is IMA ADPCM used?

Game audio, embedded systems, Windows WAV containers, and telephony devices use IMA ADPCM widely.

Related Conversions

VOX to MP3

VOX to WAV

VOX to OGG

VOX to M4A

VOX to WMA

VOX to GSM

VOX to VOC

VOX to IMA

VOX to MP2

VOX to NIST

VOX to FLAC

VOX to PVF

VOX to CVS

VOX to AAC

VOX to AC3

VOX to AIFF

VOX to AMR

VOX to M4R

VOX to DTS

VOX to OPUS

VOX to SPX

VOX to CAF

VOX to W64

VOX to WV

VOX to TTA

VOX to RA

VOX to OGA

VOX to PRC

VOX to MAUD

VOX to 8SVX

VOX to AMB

VOX to AU

VOX to SND

VOX to SNDR

VOX to SNDT

VOX to AVR

VOX to CDDA

VOX to CVSD

VOX to CVU

VOX to DVMS

VOX to VMS

VOX to FAP

VOX to PAF

VOX to FSSD

VOX to SOU

VOX to GSRT

VOX to HCOM

VOX to HTK

VOX to IRCAM

VOX to SLN

VOX to SPH

VOX to SMP

VOX to TXW

VOX to WVE

VOX to SD2

Specific converters

MP3 to IMA

WAV to IMA

MP4 to IMA

M4A to IMA

OGG to IMA

WMA to IMA

AAC to IMA

AVI to IMA

VOX to IMA

AMR to IMA

WEBM to IMA

AIFF to IMA

WMV to IMA

WVE to IMA

FLAC to IMA

MKV to IMA

AU to IMA

OPUS to IMA

3G2 to IMA

3GP to IMA

AAF to IMA

ASF to IMA

AV1 to IMA

AVCHD to IMA

CAVS to IMA

DIVX to IMA

DV to IMA

F4V to IMA

FLV to IMA

HEVC to IMA

VOX to IMA Quality Rating

5.0 (1 votes)

You need to convert and download at least 1 file to provide feedback!