VOX to TTA Converter

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.

TTA (True Audio) is a real-time lossless audio compression codec developed by Aleksander Djourik, with its origins tracing back to the early 2000s. The format reconstructs the original PCM stream bit-for-bit upon decoding, guaranteeing that no sonic detail is lost during storage or transfer. TTA handles standard CD-quality audio as well as high-resolution content up to 32-bit integer samples, making it suitable for everyday listening and professional archiving alike. Processing speed is one of TTA's defining strengths — the codec achieves fast encoding and decoding without heavy CPU demands, keeping it lightweight even on older hardware. The file structure supports ID3v1, ID3v2, and APEv2 metadata tags, so track information and album art travel with the audio. Hardware support appeared in several portable players, giving TTA a practical edge over some competing lossless formats. The open-source reference implementation ships under the GNU GPL, encouraging community adoption and third-party integrations. While newer codecs like FLAC have captured a larger share of the lossless audio landscape, TTA continues to serve users who value its simplicity and transparent compression.