Voicemail Detection

600 ms.
Decision made.

Within the first beep, your agent tells whether a caller picked up — or their mailbox did. It then leaves a personalised message, holds silence, or retries later — whichever behaviour our team sets for your campaign.

Outbound dial · +44 20 ★★ 0922
campaign_3xc · attempt 1 of 4
Voicemail detected
ring 1ring 2ring 3decision · 612 msbeep
Greeting cadencescripted
Beep proximity+ 480 ms
DecisionVOICEMAIL · 0.94
How it decides

Three signals.
One verdict.

Convexa fuses three real-time signals into a single voicemail decision — robust to short greetings, carrier-supplied messages, and noisy lines.

Greeting cadence

Scripted, mailbox-style greetings have a different rhythm than a real “hello?” Convexa’s classifier picks it up in under 500 ms.

Beep detection

Acoustic detector for the post-greeting beep. Works across carrier mailbox tones and the long-tail of weird custom prompts.

Carrier SIP info

Where the carrier passes “voicemail” in the SIP signaling, we lean on it. Where they don’t, we fall back to acoustic.

What to do next

Three options.
We set them per campaign.

Different industries want different behaviour. We support all three modes and set the right one for you — per agent or per campaign — which makes voicemail strategy a key lever for AI lead qualification.

Hang up silently

Best for sales campaigns where leaving a voicemail hurts more than it helps. The dial drops, the retry counter increments.

“…” (silent hang-up · 220 ms after beep)

Retry later, smarter

Skip the voicemail and try again at a different time. Convexa’s learned schedule picks the window this number is most likely to answer.

“…” (silent · retry scheduled for Wed 6:40 pm caller-local)
Accuracy

Measured per
region and carrier.

Carrier behaviour varies. We share per-region detection figures so you have a realistic picture before your first campaign goes live.

RegionCarriers coveredDetection rateFalse-positive rateMedian latency
United Kingdom1498.7%0.31%684 ms
Ireland598.4%0.34%702 ms
European Union7497.9%0.42%720 ms
United States11899.4%0.18%612 ms
Canada2299.1%0.22%640 ms
India997.2%0.55%760 ms
Australia698.4%0.33%700 ms
UAE497.6%0.48%740 ms

Figures reflect a rolling 90-day average. Actual results vary by deployment, market, and call mix. False-positive = a real person classified as voicemail. We review and tune these numbers as part of managing your campaigns.

Callback awareness

When they call you
back, we know.

A caller you left a voicemail for who rings back gets routed to an agent that already has the original context. The new conversation picks up from where the voicemail left off, and can hand off to your team when needed.

Inbound · +44 20 ★★ 0922
“Hi, returning a call from Northwind Solar?”
AGENT MEMORY
left a voicemail at 14:22 · re: Thursday roof survey · sentiment unknown
AGENT REPLIES
“Hi Priya — thanks for calling back. I left you a note about your Thursday survey. Want to keep it, or push it out?”
Built to scale,
human by design.

We turn on voicemail detection by default for every outbound campaign we run for you.