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G.711 codec: μ-law, A-law, and 8 kHz phone audio
G.711 is the codec most phone calls use: 8 kHz, 8 bits per sample, μ-law or A-law. How it works, how to decode it, and what it means for voice agents.
Text to speech with emotion: how to direct it
How emotional text to speech works: emotion read from the text, tags, speaking styles, and prompts across the main APIs, with code and how to test it.
What is DTMF? Tones, frequencies, and voice AI
DTMF is the pair of tones a phone sends when you press a key. How the tones work, how they travel over VoIP, why digits go missing, and what voice agents do.
IVR testing: types, tools, and voice agent tests
How to test an IVR: functional, regression, load, and speech tests for phone menus, plus how to test an AI voice agent whose answers change on every call.
OpenAI Whisper API pricing 2026, model by model
Whisper costs $0.006 a minute. Every OpenAI transcription price in 2026, the February 2027 shutdown, and what to move to before it.
Deepgram pricing 2026: STT, TTS, and agent costs
What Deepgram costs in 2026: per-minute speech-to-text rates, Aura and Flux TTS, the Voice Agent API tiers, add-ons, and the Growth plan.
Conversational AI examples: 12 real deployments
Twelve conversational AI examples running in production: support, healthcare, housing, lending, sales, and games. What each one does and what changed.
Best open-source TTS models, compared by license
Kokoro, Chatterbox, Piper, Orpheus, VibeVoice, XTTS and more: which open-source TTS models you can ship commercially, and how they score.
Conversational AI in banking: customer calls
Conversational AI in banking answers customer calls. Which calls it handles, where the line goes, how to keep card data out of the model, and how to pilot.
Conversational AI in healthcare: patient calls
Conversational AI in healthcare answers patient calls. What it handles well, where the clinical line goes, what HIPAA requires, and how to pilot it.
What is a warm transfer? Warm vs cold transfer
A warm transfer introduces the caller before handing them over; a cold transfer doesn't. How each works, when to use it, and how voice agents hand off.
WebRTC vs WebSocket for real-time voice AI
WebSocket sends ordered messages over TCP. WebRTC sends media over UDP with jitter buffers and loss recovery. Which to use for voice AI, and where.
Contact center automation: what to automate first
Contact center automation, layer by layer: which calls to automate first, what a voice agent needs to resolve them, what it costs, and what to measure.
What is SIP trunking? How it works for voice AI
SIP trunking carries calls between your phone system and a carrier over the internet. How it works, SIP vs VoIP, and connecting a trunk to a voice agent.
What is a mean opinion score (MOS)?
MOS is a 1–5 average of listener ratings. Here's how it's calculated, what a good score is for calls and for TTS, and why two MOS numbers rarely compare.
Conversational AI design for voice agents
Conversational AI design for voice: how to write for the ear, handle turns and interruptions, confirm what matters, and plan the failure paths and handoffs.
AI voice agent platforms compared (2026)
Vapi, Retell, Bland, Synthflow, ElevenLabs, LiveKit, Pipecat, and Cartesia compared: what each platform runs for you, what a minute costs, and how to pick.
What is neural TTS? How neural voices work
Neural TTS uses a trained neural network to turn text into speech. How it works, how it differs from standard voices, and what "neural" costs on a bill.
Best speech to text models compared (2026)
Streaming versus batch, API versus open source: the speech-to-text models that matter in 2026, what each is good at, and how to pick one.
ElevenLabs pricing 2026: plans, credits, and API
What ElevenLabs costs in 2026: the six plans, how credits turn into minutes, API rates per model, agent call pricing, and what a real workload adds up to.
Build a voice agent with Pipecat and Cartesia
Pipecat wires the pipeline; Cartesia supplies the voice. Get a working browser voice agent running, then cut its response time with Ink's eager turn ends.
AI cold calling: what it is and how to build one
AI cold calling is a voice agent that dials, qualifies, and books meetings on its own. What the calls cost, the consent law, and two ways to build one.
On-premise voice AI: what it is and how it works
On-premise voice AI runs speech recognition, language models, and text to speech inside your own network. Compare cloud, VPC, on-prem, and air-gapped options.
Voice AI companies to know in 2026
Who builds voice AI, grouped by what they actually do: speech model providers, voice agent platforms, cloud speech services, and open source.
AI voice agent: what it is and how to build one
What an AI voice agent is, the pipeline that runs one, and the latency, turn-taking, and testing decisions that decide whether callers stay on the line.
Voice activity detection: VAD for voice agents
Learn how voice activity detection works, how it differs from turn detection, and how to handle pauses and interruptions in a real-time voice agent.
Word error rate: what WER misses in voice AI
Learn what word error rate measures, why it can mislead TTS evaluations, and how to test the speech quality that matters in a live conversation.
What is conversational IVR? Replacing phone menus
Conversational IVR lets callers say what they need instead of pressing keys. How it routes calls, where voice agents fit, and what to test first.
What a frozen acoustic judge changes about ASR hallucination
A new speech-recognition study reduces insertion errors on meeting audio. Its results show why error types deserve attention alongside overall word error rate.
AI call center: how to pilot voice agents
Plan an AI call center pilot: choose a support queue, connect tools, test human handoffs, and measure resolution and cost before expanding.
How to compare TTS APIs using endpoint-level benchmarks
Compare TTS APIs using endpoint-level evidence. A closer look at Coval's Qwen3 entries shows what latency numbers can tell you and how to test a shortlist for production.
AI receptionist: what to buy, what to build
Compare ready-made AI receptionists with a custom voice agent. Plan scheduling, human handoffs, costs, and a test for your first inbound calls.
JavaScript text to speech with SpeechSynthesis
Build a browser text-to-speech demo with JavaScript: load voices, speak text, and stop playback. Learn when to use a hosted TTS API instead.
What Coval's streaming STT benchmark reveals about inference latency
Baseten sits on Coval’s quality–latency frontier. This brief explains what Coval measured, why dedicated inference moves the numbers, and how to reproduce low‑latency STT in production.
Python text to speech: save audio as a WAV file
Turn text into a WAV file with Python and the Cartesia SDK. Set up an API key, choose a voice, and fix common audio and authentication errors.
15 Speechify alternatives, free and paid
Speechify alternatives for listening to documents or building with speech, including which options are free and what each tool actually does.
ElevenLabs Alternatives: 10 Options Compared
ElevenLabs alternatives compared by the job: real-time voice agents, scripted voiceover, document reading, and media editing, plus a test plan.
10 Descript alternatives to consider
Compare Descript alternatives for recording, transcript editing, video production, and speech APIs. See which parts of your workflow each tool covers.
10 Google Cloud Text-to-Speech alternatives to consider
Compare Google text-to-speech alternatives by API workflow, language support, speech controls, and deployment requirements.
11 Murf AI alternatives to consider
Compare Murf AI alternatives for scripted narration and speech APIs. Test editing, exports, and streaming before choosing a tool.
How to use text-to-speech on Discord
Use Discord's /tts command, set playback and notification preferences, and troubleshoot messages that are not read aloud.
Hume AI alternatives after the TTS and EVI sunset
Hume is shutting down its TTS and EVI APIs on November 13, 2026. Compare 10 alternatives for Octave and EVI, and what to move before access ends.
Lovo AI is offline: 9 Genny alternatives
Lovo AI and its Genny app have been offline since Lovo filed for Chapter 7 in May 2026. What Genny users can recover, and 9 alternatives by job.
Amazon Polly pricing, free tier, and 11 alternatives
Amazon Polly costs $4 to $100 per million characters depending on the voice engine, with a free tier on each. Here's the full price list, then 11 alternatives.
11 Fliki alternatives to consider
Compare Fliki alternatives for narrated videos and speech generation. See which tools assemble videos and which supply audio.
Azure Text to Speech pricing, free tier, and 10 alternatives
Azure Text to Speech costs $15 per million characters for neural voices, with 500,000 free each month. Here's the price list, custom voice access, then 10 alternatives.
10 Narakeet alternatives to consider
Compare Narakeet alternatives for narration and speech APIs. Check slide timing, pronunciation, and the steps needed for a finished video.
15 PlayHT alternatives after the shutdown
PlayHT shut down on December 31, 2025. Compare 15 alternatives by the job you need done, and see what a migration can still recover.
11 Resemble AI alternatives to consider
Compare Resemble AI alternatives for custom voices and speech generation. Check consent, voice consistency, deployment options, and usage rights.
10 Respeecher alternatives to consider
Compare Respeecher alternatives for voice cloning and generated dialogue. Learn how text-to-speech differs from converting a recorded performance.
10 Speechelo alternatives to consider
Compare Speechelo alternatives for voiceovers, document reading, and speech APIs. Check purchase terms, revisions, and commercial exports.
10 Typecast alternatives to consider
Compare Typecast alternatives for scripted and interactive voices. Test delivery controls, speaker consistency, and interruption handling.
10 WellSaid Labs alternatives to consider
Compare WellSaid Labs alternatives for business narration and voice applications. Test script review, pronunciation corrections, and API behavior.