Utilities

ChirpHound: Smoke Alarm Finder

Find which alarm is chirping

iOS for iPhone and iPad

  • $2.99 one-time purchase
  • No account
  • No ads or app telemetry

View on the App Store

Good to know

How it works

  1. Tap Start listening and hold your phone still. Chirps can be a minute apart, so a quiet wait is normal.
  2. ChirpHound times the chirps: how many it has heard, how often they come and when the next one is due.
  3. Add your alarm locations and stand under each one for a chirp. It compares the sound level at your phone under each alarm.
  4. Check the strongest candidate first, and confirm it with the alarm's light, label or test button.

Honest limits

  • It compares sound levels at your phone. It does not point in a direction or measure distance.
  • Echoes can make the wrong room sound louder, which is why it asks you to check the leader again.
  • It is not a smoke or CO alarm or a monitoring service, and it cannot tell you a home is safe. If an alarm is sounding, leave and follow its instructions.
  • Sound is analyzed live on your phone and is never recorded or sent anywhere.

About ChirpHound: Smoke Alarm Finder

That periodic chirp is real. ChirpHound helps you investigate it with a clear path from listening to a recorded follow-up.

GET THE ANSWER, NOT JUST THE LOCATION
• Chirp Verdict pairs the measured cadence with a short set of plain questions: kind, brand, power type (replaceable, sealed 10-year, hardwired), wiring, whether a new battery stopped the chirp, the label date, and timing.
• One card with receipts: low battery, still chirping after a new battery (residual-charge reset), end of life (replace the unit, not the battery), past replace-by guidance, hardwired chain (find the unit on backup power), or a model-specific code.
• Sourced fix steps; a three-beep or four-beep safety pattern is never softened.
• No microphone needed for the questions: answer from what you know, then confirm with a measured cadence.

SCAN THE LABEL
• Read the model number and label date from a photo of the alarm's label, on this device, then confirm or correct what was read.
• Open the manufacturer's own support page (Kidde, First Alert/BRK, Nest Protect, USI) or the USFA guidance; an exact manual is linked only when the model is recognized.
• Manual entry stays available.

FOLLOW THE CHIRP
• Listen: choose a preset or use Auto Discover; a progress panel shows settling, listening time, level relative to the room, chirps heard and the predicted next chirp, with one next action.
• Learn target: learn a numeric fingerprint from repeated chirps to help separate similar sounds.
• Compare: a guided 3·3·3 sequence — three readings at your reference, three at another position, three back — captures each chirp for you; changed input, clipping and low signal-to-noise readings still never join a comparison.
• Inspect: record the device/model and location you physically observed, your own identification, and any action taken or planned.
• Verify: keep the same microphone and target active for a chosen window and record what happens next.

KEEP THE EVIDENCE
Each capture keeps its input segment, target, band energy, background estimate and exclusion reason. Resume saved searches; export the ledger as CSV or a paginated PDF field report.

FIELD TOOLS WHEN YOU NEED THEM
• Live spectrogram, 24-band Auto Discover, 15 presets and a next-chirp clock
• Manual chirp marks and pattern suggestions
• HoundMap checkpoints, EchoMap room observations and optional ChirpMesh nearby sessions
• Hearing Assist options for visual, haptic, spoken and headphone cues
• Not hearing it? troubleshooter with wait guidance
• Email support: a prefilled, numbers-only draft you review before sending
• 19 synthetic Signal Lab scenes, 48 checklist entries, 24 field guides and 22 reference patterns (16 cited to standards or manufacturer pages)

MEANINGFUL LIMITS
Comparisons require one unchanged input and target, repeated readings, and a return to the reference; short chirps may need more readings. The app does not measure movement, calibrate microphones or infer distance, direction or probability. No matching chirp during a timed window is an observation, not proof of repair or safety. A verdict interprets your answers and the measured cadence; codes vary by manufacturer and model, the label and manual govern, and the app never states that an alarm is safe. Label reading is text recognition on your photo — check it against the label. Synthetic-room tests validate the software, not your room, microphone or alarm.

PRIVATE BY DESIGN
Audio is analyzed live on the device and is not recorded or transmitted. The camera is used only when you tap Scan the label; the photo is processed in memory and never stored or sent. Support email is composed by you and sent from your own mail app. No account, advertising, analytics or tracking. Records stay on the device unless you share a report.

ChirpHound is a locating and reference aid, not a smoke alarm, CO alarm, sound-level meter or substitute for emergency action. If a real alarm is sounding, leave the area and follow its instructions.

A Shadowfetch app. Published on the App Store by Robert Corbin.