Measure reverberation, by iPhone.
Lab-grade T20 and T30 across octave and third-octave bands using the impulse-response or sweep method. PDF and CSV export. Free tier, Plus for €16.58/mo annual.
What you get.
Six things that matter, done well, in a single iPhone app.
T20 and T30 reverberation
Reverberation time measured by Schroeder backward integration. Both T20 and T30 reported with R² fit quality per band.
Sweep + impulse methods
Choose a sine-sweep with a Bluetooth speaker for tougher acoustic environments, or a clap-style impulse for fast, casual checks.
Octave & third-octave
Frequency-band analysis from 63 Hz to 8 kHz in octaves, or 25 Hz to 10 kHz in third-octaves on Plus.
PDF + CSV export
A clean PDF for the project file, and a CSV with every band, every fit parameter, and the raw decay curve for further analysis.
Internal mic supported
The internal iPhone microphone is calibrated for the supported devices. Tap to measure — no external gear required for most rooms.
Project history
Group measurements by project and room. Compare two measurements side-by-side, before and after treatment.
From download to result in under five minutes.
Download
Get AcousticCheck from the App Store. Plus has a 30-day free trial — no card required.
Set up
Name the project and the room. Optionally connect a Bluetooth speaker for the sweep method.
Measure
Tap to record. Indoor reverberation completes in about eight seconds; sweep takes a little longer.
Export
PDF for the client, CSV for your spreadsheet. Both honor the project name and the date stamp.
Our pricing plans.
Free for casual use. Plus for working acousticians. Enterprise for teams.
Free
- T20 / T30, octave bands (63 Hz – 8 kHz)
- Impulse method
- Internal microphone
- One project / one room
- PDF export with watermark
Plus
- Everything in Free
- Third-octave bands (25 Hz – 10 kHz)
- Sweep method + speaker support
- External microphone support
- Unlimited projects, rooms, history
- PDF + CSV export, no watermark
Enterprise
- Everything in Plus
- Branded reports (your logo)
- Multi-user accounts
- Priority email support
- API access
- Custom integrations
The honest answers.
On a calibrated iPhone, T20 and T30 are typically within ±5% of a Class-2 instrument in rooms with reverberation times between 0.3 and 3 seconds. The Schroeder method is robust to ambient noise above roughly 35 dB SPL background. Each measurement reports the R² of the decay fit per band so you can see when conditions weren’t cooperating.
For laboratory-grade certification work, you still want a Class-1 instrument. For day-to-day acoustic measurement in studios, classrooms, offices, and small venues — AcousticCheck is good enough that we use it for our own consulting.
Almost none. The default workflow — place phone, tap to record, get a number — works for anyone. The more you know about acoustics, the more value you’ll get from the third-octave bands and the decay curves, but the headline numbers are read-out, not interpretation.
Pros: it’s with you always. It’s ten times faster than rigging a real meter for a quick check. The PDF goes straight to the client.
Cons: it’s an iPhone. In a 4,000-seat hall with a 3-second tail and lots of ambient HVAC, you’ll want better gear. The internal mic is calibrated, but it’s still an internal mic.
Yes, currently iOS only. Android is harder because the hardware variance is much wider — we’d rather not ship a measurement tool we can’t calibrate. It’s on the long-term roadmap.
No. For most rooms the internal iPhone mic is enough. For very large or very dead rooms, or when measuring at sub-100-Hz, an external mic — connected by Lightning/USB-C adapter or Bluetooth — gives you a cleaner signal. Plus supports common XLR interfaces.
Anything from a 2-square-meter vocal booth to a 5,000-seat concert hall, within the limits above. Outdoor measurement isn’t supported (no enclosed sound field).
30 days of Plus, free of charge.
Try the sweep method, the third-octave bands, and the PDF + CSV export with no card on file. Cancel from inside the app.