Audio Library
Upload, manage, and organize audio files used across your voice campaigns and IVR flows. The Audio Library serves as a central repository for all your voice assets with built-in playback, organization, and text-to-speech generation.
Overview
The Audio Library is the single source of truth for all audio content in your Voxvaani account. Whether you upload professionally recorded voice prompts, store call recordings, or generate speech from text using the built-in TTS engine, every audio file lives here and is accessible to campaigns, IVR flows, and XML scripts.
Audio Requirements
To ensure compatibility and reliable playback during voice calls, follow these audio specifications:
| Requirement | Recommended | Notes |
|---|---|---|
| Format | MP3 (preferred), WAV | MP3 offers the best balance of quality and file size. Avoid lesser-known codecs. |
| Sample Rate | 16,000 Hz (16 kHz) | This is the standard telephony sample rate. Higher rates (44.1 kHz, 48 kHz) are automatically resampled but may degrade slightly. |
| Bitrate | 64–128 kbps (MP3) | 64 kbps is sufficient for voice. 128 kbps for music or complex audio. Below 64 kbps introduces noticeable artifacts. |
| Channels | Mono | Stereo files are accepted but converted to mono during playback. Mono files are smaller and process faster. |
| Bit Depth | 16-bit | Standard for speech audio. 8-bit files sound harsh; 24-bit files are unnecessarily large. |
| Duration | Under 60 seconds per file | Shorter files load faster and reduce per-call latency. For long messages, split into shorter segments. |
| File Size | Under 10 MB | Maximum upload size is 25 MB. Files larger than 10 MB may cause playback delays at call time. |
File size and storage: Maximum upload size is 25 MB per file. Your plan includes a total storage quota for audio files (check your plan limits under Billing). Files that exceed the size limit are rejected on upload. Regularly clean up unused audio files to stay within your storage quota. Audio files referenced by active campaigns cannot be deleted — pause or complete the campaign first.
Features
Upload Audio
Upload audio files through the web interface:
- Navigate to Audio Library from the sidebar.
- Click Upload Audio (or drag and drop files onto the library page).
- Select one or more files from your computer. Supported extensions:
.mp3,.wav. - The system validates file format, size, and duration during upload. Invalid files are flagged immediately.
- Uploaded files appear in the library with the original filename. Rename files for easier identification — use descriptive names like
welcome_greeting_hi.mp3orpayment_reminder_en.mp3.
Supported formats:
| Format | Details | Recommended For |
|---|---|---|
| MP3 | Best compression-to-quality ratio. Universal compatibility. | General campaign messages, IVR prompts |
| WAV | Uncompressed, highest quality. Larger file size. | Music, jingles, or when editing is planned |
TTS Generation
Convert text to speech directly within the library without leaving the interface:
- Click Generate Voice.
- Choose a Language (Hindi, English, Tamil, Telugu, and more — see the TTS Generator documentation for the full list).
- Select a Speaker Voice — preview samples by clicking the play icon.
- Enter your Text (up to 1,000 characters per generation).
- Click Generate. Processing completes in 3–10 seconds.
- The generated audio appears in your library automatically with a descriptive filename.
For detailed guidance on TTS quality, language options, and best practices, see the TTS Generator documentation.
Managing Files
The Audio Library provides the following actions for each file:
| Action | Description |
|---|---|
| Play | Inline audio preview with playback controls (play/pause, seek, volume). Verify audio quality and content before using in campaigns. |
| Rename | Change the file name for better organization. Useful when uploading files with generic names. |
| Download | Save a copy of the audio file to your local device. |
| Delete | Permanently remove the file from the library. Files referenced by active campaigns cannot be deleted. |
| Refresh | Reload the file list to reflect recent uploads or changes. |
Bulk Operations
For libraries with many files, use these bulk actions to manage efficiently:
- Select Multiple: Use the checkbox column to select multiple files simultaneously.
- Bulk Delete: Remove multiple unused files at once. The system warns if any selected files are linked to active campaigns.
- Bulk Download: Download selected files as a ZIP archive for backup or offline editing.
- Search and Filter: Use the search bar to find files by name. Filter by format (MP3, WAV) or source (Uploaded, TTS Generated).
Audio Quality Best Practices
High-quality audio directly impacts campaign effectiveness. Listeners disengage quickly from poor-quality voice messages.
| Practice | Recommendation |
|---|---|
| Normalization | Normalize audio to -3 dB peak level before uploading. This ensures consistent volume across all your messages and prevents jarring volume changes between prompts. |
| Silence Trimming | Remove leading and trailing silence from audio files. Even 1–2 seconds of silence at the start makes callers think the call dropped. Trim silence to under 0.5 seconds at both ends. |
| Background Noise | Record in a quiet environment with minimal echo. Background hum, traffic noise, or room reverb are amplified during telephony compression and sound unprofessional. |
| Audio Peak Levels | Avoid clipping (audio exceeding 0 dB). Clipped audio sounds distorted and harsh over phone lines. Use a limiter during recording or post-processing. |
| Consistent Voice | Use the same speaker or TTS voice across all prompts in a single campaign or IVR flow. Switching voices mid-call confuses and disorients listeners. |
| Test on Actual Phone | Always play your audio through an actual phone call (not just computer speakers) before launch. Telephony compression can reveal issues not apparent in direct playback. |
Using Audio in Campaigns
Audio files in your library are referenced throughout the platform:
In Voice Campaigns
When creating a campaign with the Audio calling type, select any file from your Audio Library as the message to play. The file is fetched by the telephony provider at call time and streamed to the recipient.
In IVR Flows
Drag a Speech or Play Audio node onto the IVR canvas, then select an audio file from your library. Each node can reference a different file, allowing you to compose a complete call flow from individually managed audio segments.
In XML Scripts
Reference audio files by their public URL in VoxiXML <playaudio> elements. Files uploaded to the Audio Library are automatically assigned public, HTTPS-accessible URLs. To find a file’s URL, click the file in the library and copy the URL from the details panel.
<playaudio>https://cdn.voxvaani.com/audio/abc123/welcome_greeting.mp3</playaudio>Organize by language and purpose. Use a consistent naming convention for audio files: {purpose}_{language}_{variant}.{ext} — for example, welcome_hi_v2.mp3, payment_reminder_en.mp3, survey_q1_ta.mp3. This makes it easy to find the right file when building campaigns, especially with large libraries.
Tips
- Use meaningful, descriptive filenames for easy identification — avoid generic names like
audio1.mp3. - Test audio quality by playing files on an actual phone call before launching to a full contact list.
- Generate TTS in the same language as your target audience for maximum comprehension.
- Keep audio messages under 60 seconds for better listener engagement and lower voice minute consumption.
- Regularly audit your library and remove unused files to stay within your plan’s storage limits.
- For frequently updated content (daily deals, stock prices), use TTS generation instead of re-recording audio every day.