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Appliance Noise Frequency Identifier

This appliance noise frequency identifier answers "what’s that hum, buzz, or whine?" — point your microphone at the appliance and it finds the dominant frequencies in the noise and suggests the likely source — mains hum, a compressor or motor, transformer buzz, or coil whine — with a live spectrum and the top tonal peaks.

🔎 This is a frequency-based heuristic, not a definitive diagnosis. Many appliances share frequencies, so treat the suggestion as a starting point. Get the mic close to the source and keep other noises quiet.

🔒 Runs entirely in your browser. No audio is recorded, uploaded, or stored.

Microphone

Input device

Idle — press Start, then hold the mic near the appliance.

Dominant tone

—

Listening…

Top tonal peaks

FrequencyLevelLikely source

No clear tones yet — start listening near the noise.

A steady appliance hum shows one or two strong peaks (often at 50/60 Hz or 100/120 Hz, plus the mechanical tone). Coil whine appears high up (1–10 kHz). If everything is low and flat, it’s broadband noise with no single tone.

Live noise spectrum (log frequency) — detected peaks marked

Reading the Noise

Most annoying appliance noises are tonal — they sit at one pitch (a hum, buzzing noise, or whine) rather than a broad hiss. Every tone has a frequency, and many appliances produce characteristic frequencies, so measuring the pitch narrows down the cause and helps you find the noise source. This tool captures your microphone, runs a fast Fourier transform (FFT), and picks out the strongest narrow peaks, then matches the dominant one to a table of common sources. The live spectral analysis view lets you see both the fundamental tone and any harmonics at once, which is often the clearest clue to the source.

The single most common culprit is mains hum: a tone at your country’s power-line frequency (60 Hz in the Americas, 50 Hz most elsewhere) and its harmonics (120 Hz / 100 Hz, etc.). It comes from transformers, power supplies, dimmers, and the electronics inside appliances — often accompanied by harmonic distortion that produces a ladder of peaks at multiples of the fundamental. Mechanical noise — a fridge or AC producing a compressor noise, a pump, a fan — tends to sit a bit higher (tens to a few hundred Hz) and may also show blade-pass frequency sidebands. Coil whine from power supplies, GPUs and chargers is a high-pitched tone, often 1–10 kHz, caused by magneto-mechanical vibration resonance in wound components at their switching frequency.

Rough frequency → likely source guide

50 / 60 Hz — mains hum (transformer, PSU, ground loop, dimmer).
100 / 120 Hz — mains 2nd harmonic; transformer/ballast core, fridge & AC electronics, fluorescent/LED drivers.
20–120 Hz broadband — low rumble: HVAC, compressors, washing machines, large fans.
120–400 Hz — compressor or motor hum (fridge, AC, pumps).
400–1500 Hz — motor/fan whine, blade-pass tones, spinning drives.
1.5–10 kHz — coil whine (PSU/GPU/charger), switching supplies, fan bearings.
~15.7 kHz — old CRT TV/monitor flyback whine.

Why it’s only a guess

Frequency alone can’t uniquely identify an appliance — a 120 Hz tone could be a transformer, a fridge, or a fluorescent light. Room acoustics, your mic, and overlapping sources all blur things. Use the reading to narrow the search (e.g. "it’s electrical hum, not mechanical"), then confirm by switching appliances off one at a time and watching which peak disappears. For a deeper view of your room’s full frequency profile, the audio spectrum analyzer offers a full-resolution FFT with peak hold and A/C/Z weighting — useful when you want to study a noise floor rather than just a single tone.

If you already know the problem is at 50 or 60 Hz and want a tool that locks onto mains hum specifically, the hum frequency detector is purpose-built for tracking that fundamental and its harmonics, including ground loop noise in audio equipment.

Frequently Asked Questions

How do I find which appliance is making the noise?

Start listening, note the dominant frequency, then switch suspect appliances off one at a time. When the peak on the spectrum drops, you’ve found the source. Getting the mic within a few centimeters of each candidate also makes its tone dominate, helping you isolate it.

It says "mains hum" — what does that mean?

A strong tone at 50 or 60 Hz (or 100/120 Hz) is electrical hum from the power line, common to transformers, power supplies, chargers, dimmers, and ground loops. It’s usually electrical rather than mechanical. If it’s coming through your audio gear, look at grounding and cabling; if it’s acoustic from a device, it’s often a transformer or ballast.

What is coil whine?

A high-pitched tone (commonly 1–10 kHz) from electronic components — inductors/coils in power supplies, GPUs, laptop chargers and LED drivers vibrating at their switching frequency. It’s usually harmless but annoying. This tool flags high-frequency tones as likely coil whine.

Why does the identification jump around?

If no single tone dominates, the strongest peak flickers between competing sources and background noise. Move the mic closer to the appliance you’re investigating and reduce other noise so one peak stands clearly above the rest.

Can it tell 50 Hz from 60 Hz?

Yes — it uses a high-resolution FFT, so 50 Hz and 60 Hz land on clearly separate frequencies. That distinction can even hint at region or a specific device (e.g. an imported transformer humming at the "wrong" mains frequency).

Is the suggestion definitive?

No. It’s a frequency-based heuristic — several appliances share frequencies, and the tool only sees the pitch, not the device. Treat it as a clue that points you in the right direction (electrical vs mechanical, low vs high), then confirm by elimination.

Does it disable noise suppression?

Yes — it requests the raw signal with noise suppression and auto-gain off, so steady appliance tones aren’t filtered out. If your OS forces noise suppression, it may remove exactly the hum you’re trying to find; disable microphone "enhancements" in system settings.

Is any audio recorded?

No. The signal is analyzed in real time to find tonal peaks only; nothing is recorded, saved, or transmitted. The microphone is released when you press Stop or close the tab.

My fridge makes a buzzing noise — what frequency should I expect?

A refrigerator compressor typically hums between 50–120 Hz, often coinciding with or just above mains frequency because the compressor motor runs on AC power. If the buzz is clearly electrical (heard from the electronics or control board), it will likely land right at 60 Hz or 120 Hz. A mechanical rattle from a loose panel or compressor mount produces a broadband low rumble rather than a clean tonal peak — you will see a wide mound on the spectrum rather than a sharp spike.

What is the difference between tonal noise and broadband noise?

Tonal noise has energy concentrated at one or a few specific frequencies, producing sharp peaks on the spectrum — a hum, buzz, or whine. Broadband noise spreads energy across a wide range of frequencies, appearing as a raised floor or smooth hump rather than spikes — typical of airflow, fans running at speed, or rushing water. This tool is most useful for tonal noise; broadband rumble from HVAC or turbulent airflow will not produce a clear dominant-frequency reading.

Can I use this to identify HVAC or air-conditioning noise?

Partially. HVAC systems produce a mix of broadband airflow noise and tonal components from the compressor (50–120 Hz), blower motor (often 100–300 Hz), and duct resonance. The tool can detect the tonal components if they stand out above the airflow hiss. Compressor cycling noise will appear as periodic low-frequency peaks; duct resonance often shows up as a sharp peak in the 80–250 Hz range. The broadband airflow component itself will not yield a single identifiable frequency.

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