Glossary
AI phone agents, term by term
34 terms that come up when a business looks at AI phone agents, from the telephony plumbing to the compliance words on every procurement checklist. Each one is written to be read on its own.
The basics
The four terms that get used interchangeably in sales conversations and mean different things.
- AI phone agent
- An AI phone agent answers inbound calls in natural speech, understands what the caller wants and completes the task in the business's own systems, for example booking an appointment or logging a request. Unlike a phone menu it has no fixed script and no keypad options.Full page
- Voicebot
- A voicebot is any software that holds a spoken conversation. The word covers everything from a rigid phone menu to a full AI phone agent, which is why it says little about capability on its own.Full page
- AI agent
- An AI agent is a system that pursues a goal across several steps and may call external tools along the way, rather than answering a single question. A phone agent is one kind of AI agent, with the telephone as its channel.Full page
- Phone answering service
- A phone answering service takes calls on a business's behalf. Traditionally that meant a call centre staffed by people and billed per call or per minute; the same job is now also done by software.Full page
Telephony
The plumbing. Mostly words your phone provider uses, and the ones that decide how an agent gets connected at all.
- IVRInteractive Voice Response
- IVR is the phone menu that asks callers to press 1 for sales and 2 for support. Choices are fixed, defined in advance, and a caller whose request fits no option usually ends up waiting for a person.
- ACDAutomatic Call Distribution
- ACD decides which phone rings when a call comes in, based on rules such as team, skill, time of day or who has been idle longest. An AI phone agent is normally added as one more destination in these rules.
- SIPSession Initiation Protocol
- SIP is the protocol that sets up and ends calls over the internet. A SIP trunk is the line between a phone system and a provider, and it is the usual place where an AI phone agent is attached without changing the number.
- CTIComputer Telephony Integration
- CTI links the phone system to business software, so an incoming number can open the matching customer record. It is the older, screen-focused ancestor of what an AI phone agent does on its own.
- Call forwarding
- Call forwarding sends calls from one number to another, either always, only outside business hours, or only when nobody picks up. It is how an AI phone agent is usually connected, because it needs no number porting and can be switched off again in minutes.
- Number porting
- Porting moves a phone number from one provider to another permanently. Porting takes days to weeks and is not required to use an AI phone agent, which is what call forwarding is for.
- Call queue
- A call queue holds callers until someone is free. Queues are where abandonment happens: most callers to a small business hang up rather than wait, and a hung-up call leaves no record of what it was about.
- Answer rate
- Answer rate is the share of inbound calls that get picked up rather than ringing out or being abandoned in a queue. It is the single number that shows what a missed-call problem actually costs.
Speech and models
What actually happens between the caller speaking and the agent answering, and the words vendors use to describe how well it goes.
- Speech-to-text (STT)Also: ASR, automatic speech recognition
- Speech-to-text turns what the caller says into written words. Accuracy on accents, background noise and proper nouns such as street or medication names is what separates usable from frustrating on the phone.
- Text-to-speech (TTS)
- Text-to-speech turns the agent's written answer back into a voice. Modern systems produce speech most callers do not identify as synthetic within the first sentence.
- NLUNatural Language Understanding
- NLU is the step that works out what a sentence means rather than what words it contains. It is what lets a caller say 'I need to move Thursday' instead of picking option three.
- Intent
- An intent is the goal behind a call, such as booking, rescheduling, a price question or an emergency. Routing, reporting and the decision to hand over to a person all hang off which intent was recognised.
- Entity
- An entity is a concrete value pulled out of what the caller said: a date, a name, a customer number, a treatment. Intents say what someone wants, entities say the specifics.
- Barge-in
- Barge-in is the agent stopping mid-sentence when the caller starts talking. Without it a conversation feels like an announcement, because the caller has to wait for the system to finish before saying anything.
- Turn-taking
- Turn-taking is judging when the caller has finished a thought rather than merely paused. Getting it wrong produces the two classic failures: interrupting someone mid-sentence, or leaving an awkward silence.
- Latency
- Latency is the delay between a caller finishing and the agent starting to answer. Above roughly one second a phone conversation starts to feel broken, so latency matters more here than in chat.
- LLMLarge Language Model
- An LLM is the model that produces the agent's answers. On the phone it works inside guardrails and with access to live business data, because a model on its own can neither see a calendar nor book anything.
- Hallucination
- A hallucination is a confident answer that is not true. On the phone the defence is not a better model but a narrower one: the agent reads facts out of connected systems and hands over when it has no source.
Running it
How an agent connects to the rest of a business, and what comes back out of every call.
- Handoff
- A handoff is passing a live call to a person. A good one arrives with the caller identified and the request summarised, so nobody has to start the conversation again from the beginning.
- Escalation
- Escalation is the rule set that decides which calls must reach a human immediately: medical emergencies, angry callers, anything legally sensitive. Escalation rules are defined by the business, not by the model.
- Call summary
- A call summary is the short structured record written after a call: who rang, what they wanted, what happened. It is what turns a phone call into something the rest of the team can act on.
- Transcript
- A transcript is the full written record of a call, turn by turn. Transcripts are what make an agent auditable: a disputed answer can be read back rather than argued about.
- Webhook
- A webhook is an automatic message another system receives when something happens, for example a call ending. Webhooks are how call events reach automation tools without anyone writing integration code.
- API scope
- A scope is the specific permission an integration is granted, such as reading availability or creating an appointment. Scopes are the difference between an agent that can book a slot and one that can see a whole patient file.
- Two-way sync
- Two-way sync means changes flow in both directions: a booking made by the agent appears in the calendar, and a cancellation made in the calendar is known to the agent. One-way sync is where double bookings come from.
Law and compliance
The words that appear on every German procurement checklist, and what they actually require.
- GDPRGeneral Data Protection Regulation
- GDPR is the EU regulation governing personal data. For a phone agent it decides three things above all: where the data is processed, how long recordings and transcripts are kept, and what callers must be told.
- DPAData Processing Agreement
- A DPA is the contract required whenever one company processes personal data on another's behalf. Any AI phone agent handling caller data needs one in place before the first real call, not after.
- EU AI Act
- The EU AI Act classifies AI systems by risk and attaches duties to each class. For a phone agent the practical consequence is a transparency duty: callers have to be able to tell they are speaking to a machine.
- Data residency
- Data residency is the physical location where data is stored and processed. For German buyers it is usually the first question asked, and hosting inside the EU is often a hard requirement rather than a preference.
- Recording notice
- A recording notice is the sentence at the start of a call telling the caller the conversation is recorded. In Germany recording without notice is not permitted, which is why the notice belongs in the agent's first message.
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