Pitch Hunter

Pitch Hunter turns your iPhone into a pocket lab for the sounds around you — and the sounds you can't quite hear.

Point it at a speaker, a mosquito, or a wall that hums at 2 a.m. and see the frequency, the note name, and the energy across the spectrum in real time. Pitch Hunter listens up to the limit of your microphone and shows you what's there.

— What's inside —

DETECT A live 48 kHz spectrogram with a peak-hold pitch tracker and a lock-state gauge that firms up as a signal holds steady. Band presets for Mosquito (14–20 kHz), Electronics (10–20 kHz), Coil Whine (15–22 kHz), CRT Flyback (8–12 kHz), and Full Range (2–22 kHz). A built-in classifier tags mosquito wingbeats, flyback whine, ultrasonic repellers, and switching-supply noise. The gauge reads dB above a per-band ambient baseline the app measures on the fly — each band remembers the lowest baseline it has ever seen, so moving somewhere quieter sharpens the reading.

GENERATE Play any frequency from 20 Hz to 22 kHz with clean sine, square, triangle, or sawtooth waveforms. Useful for testing speakers, checking hearing thresholds, tuning instruments, and hunting rogue room resonances. A built-in Hearing Test sweeps your audible range and plots where your ears roll off. A Room Resonance Finder sweeps a tone while listening back, and flags the frequencies your walls are amplifying.

REPEL Tuned ultrasonic pulses in the 15–22 kHz band for common pests, with adjustable duty cycle, auto-shutoff up to 8 hours, and a first-run safety confirmation. Works only while the app is foregrounded — the tone cannot run in the background. A short disclaimer explains what the science does and does not support. No snake oil.

CRITTERS A curated library of animal calls organized by region — Aquatics (humpback whale, orca, bottlenose dolphin, beluga, sperm whale, blue whale), Africa, Americas, and Asia. Each species card shows the natural frequency range, the subset your iPhone speaker can actually reproduce, and a stylized preview. Europe and Down Under are scaffolded for upcoming updates.

CALIBRATION SWEEP Long-press the header to kick off a hidden sweep that measures your specific phone's microphone + speaker response curve. The app adapts its scale to your hardware so the numbers on screen are meaningful — the kind of self-test that usually needs a measurement mic.

— Built for —

• People who want to see what sound is actually in the room, not a pretty animation • Pest-control pros tracking ultrasonic deterrents • Electronics hobbyists chasing switching-supply noise • Field sound designers scouting mosquito-free locations • Biology students comparing marine-mammal vocalizations • Anyone whose hearing rolls off above 14 kHz and wants to see what they're missing

— Privacy & build —

• All analysis runs on device. No audio leaves the phone. • No account, no cloud, no tracking SDKs, no network calls. • Microphone permission only. • Accessibility-first: VoiceOver labels everywhere, full Dynamic Type, Reduce Motion opt-out. • One-time Pro unlock for Repel and Critters. No subscription.

— Important —

Pitch Hunter is an enthusiast tool, not a medical device. It does not diagnose hearing loss, tinnitus, or infestations. Repel-mode tones are below the level of general audibility for most adults but may still be perceptible to pets and young children — use at sensible volumes, especially around animals.

Questions, feature requests, or bug reports: pitchhunter@jaredgrover.com