What is GSM?

GSM 06.10 is a lossy speech codec used in GSM mobile phone networks for compressing voice calls into low bitrates.

What is VOX?

Dialogic VOX is a compressed speech audio format optimized for telephony systems, voice mail, and interactive voice response.

When Should You Use GSM vs VOX?

GSM vs VOX: Key Differences

• •GSM uses lossy compression while VOX uses lossy compression — both take the same approach to file size management.
• •Neither format changes compression philosophy — both are lossy compression — so any size differences are due to encoding efficiency, not a shift in quality approach.
• •Alpha channel support: VOX lacks transparency support.
• •File sizes: GSM files typically range Very small, 13kbps bitrate and VOX files Very small, ideal for voice storage.
• •Use case fit: GSM targets mobile voice, legacy phone recordings, voicemail and VOX targets telephone systems, voice mail, ivr systems — your choice depends on which workflow stage you are serving.

Advantages of GSM

• ✓GSM compresses data using lossy methods, keeping file sizes manageable for Mobile voice, legacy phone recordings, voicemail.
• ✓Industry-wide support means GSM files open anywhere — from legacy systems to the latest devices.
• ✓Small file sizes make GSM ideal for email, web uploads, and cloud storage.
• ✓From professional software to open-source alternatives, GSM works out of the box.

Advantages of VOX

• ✓At its core, VOX relies on lossy encoding — a design choice that makes it perfect for Telephone systems, voice mail, IVR systems.
• ✓You won't run into compatibility issues with VOX — it's a universal standard across platforms.
• ✓File size management with VOX: aggressive compression with minimal visible quality loss.
• ✓Every major application in the Telephone systems, voice mail, IVR systems space supports VOX natively.

Common Use Cases for GSM to VOX Conversion

• Music education
• Conference call recordings
• Field recording preservation
• Music production and mixing
• Podcast distribution
• Voice recordings

Industry Applications

Best Practices for GSM to VOX Conversion

• →Converting GSM to VOX: VOX uses lossy compression — choose a higher bitrate (320 kbps) for near-CD quality
• →Normalize audio levels before conversion for consistent playback volume
• →VOX excels in professional audio workflows
• →Always keep a backup of your original files before converting
• →Choose the appropriate quality settings for your specific use case

Related Article

Troubleshooting GSM to VOX Conversion

• !Clicks or pops in the converted VOX → sample rate conversion can introduce artifacts; use a clean multiple of the source rate
• !VOX file has silence at the beginning or end → trim the source GSM file before converting to avoid unnecessary padding
• !Stereo image collapsed after converting GSM to VOX → verify that the converter preserves channel mapping for multichannel audio
• !The converted VOX clips or distorts at peaks → reduce the gain or apply a limiter before conversion to prevent hard clipping

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