Glossary

Contract under Art. 28 GDPR between controller and processor. Defines purpose, scope and safeguards of data processing. Mandatory for any SaaS handling personal data.

Ability of callers to interrupt the assistant mid-sentence. Considered a marker of natural conversation; implemented via parallel STT with voice-activity detection.

Number of phone calls handleable in parallel. Defines scaling under load — critical during campaigns or emergencies. Usually plan-dependent.

Connection between phone assistant and customer-relationship system (HubSpot, Salesforce, Pipedrive). Auto-creates contacts and activities after each call.

EU General Data Protection Regulation. Governs processing of personal data in the EU. Requires legal basis, purpose limitation, DPA on processing, and EU servers for sensitive data.

Storage and processing of data exclusively in EU data centers. Reduces post-Schrems-II third-country transfer risk and is a precondition for many GDPR-compliant deployments.

Inbound = assistant takes incoming calls (booking, support). Outbound = assistant places calls (confirmations, surveys). Compliance requirements differ between modes.

Legacy voice menu system with keypad input ("press 1 for ..."). AI phone assistants replace IVR with free-form speech and intent recognition.

Software that handles inbound and outbound calls autonomously — using speech-to-text, a language model for response generation and text-to-speech. Hands off to humans when needed.

Delay between end of caller speech and assistant response. Under 700 ms feels natural, over 1500 ms feels broken. Composed of STT, LLM and TTS time.

Large language model (GPT-4, Claude, Llama) used to generate responses. Combined with RAG in phone contexts to access company-specific knowledge.

Component that maps caller utterances to structured intents and entities ("appointment Tuesday 10am" → intent=book, slot=tue-10). Today usually handled by LLMs.

Architecture where the LLM fetches relevant documents from a knowledge base before answering. Enables up-to-date, company-specific responses without fine-tuning.

Internet-based phone line forwarding numbers to the AI assistant. Standard VoIP protocol. Frequently ported from existing carriers (Deutsche Telekom, Sipgate, Vodafone).

Contractually guaranteed service quality: availability (e.g. 99.9 %), response time, recovery time. Mandatory for business-critical deployments, often with penalties on breach.

Converts spoken language to text. Also called ASR (Automatic Speech Recognition). Quality drives understanding rate; specialized models per language are essential.

Converts text into spoken audio. Modern neural TTS sounds nearly human. Differs in latency, language coverage and voice-cloning capability.

Umbrella term for AI systems that understand and produce speech. Encompasses STT, NLU/LLM and TTS. AI phone assistants are a concrete application of Voice AI.

Synthesis of a voice from a sample (typically 30 s–10 min). Enables consistent brand voice. Requires GDPR and consent-law review before deployment.

HTTP callback that notifies a third-party system on call events (call ended, appointment booked). Most common integration technique alongside direct APIs.