A cat hears from 48 Hz to 85 kHz. A young person covers roughly 64 Hz to 23 kHz, which leaves about 3 octaves at the top of the cat's band that no human ear can use — and that invisible band is what turns an ordinary vacuum cleaner into a panic event. The working rule: keep steady household noise under 50 dB(A), keep anything above 80 dB(A) out of the room where the cat sleeps, and never read silence as comfort.
48 Hz to 85 kHz, compared with other ears
Start with the endpoints, because they explain the behavior. Bottom of range: 48 Hz for a cat, 64 Hz for an adult person, 67 Hz for a dog. Top of range: 85 kHz for a cat, 23 kHz for a person, 45 kHz for a dog. Counted in octaves, that is about 10.8 for the cat against 8.5 for the human. The gap at the ceiling is the part that matters: the span from 10 kHz to 85 kHz is 3 full octaves of ultrasound. Mice and rats vocalize across 20–60 kHz, so a cat can follow a mouse moving behind 2 cm of plasterboard from 4–5 m away. A dog at 35 kHz is close to its ceiling; a cat still has 50 kHz of headroom above that.
Age erodes the top end first. High-frequency loss is common after 8 years, and a 12-year-old cat may top out near 30–40 kHz instead of 85. That is a drop of more than 1 octave, and it changes how the cat answers a call from 10 m away in a noisy room.
Why an 80–90 dB(A) appliance hits harder than the number suggests
A vacuum rated 80–90 dB(A) at 1 m is loud to you. To a cat it is loud and dense in exactly the frequencies its ear is built to amplify. The motor whine carries energy at 20–40 kHz, the pinna adds gain above 10 kHz, and the ear canal resonates near 4 kHz. The dB(A) weighting on the spec sheet rolls off everything above roughly 8 kHz, so the figure you read was never measuring the part the cat reacts to.
Two effects stack. Loudness at 25 kHz is relatively far higher than 80 dB(A) implies, and the sound is unpredictable: a beater bar striking a rug at 1–3 Hz never settles into a rhythm a cat can habituate to. Add a start-up surge of 5–10 dB(A) in the first 2 seconds and the device clears a room in under 10 seconds. Watch for 3 signals inside 30 seconds — ears rotated back, tail tip flicking at 1–2 Hz, a low crouch with the body flattened — and treat 3 out of 3 as a decision to leave.
32 muscles per ear, and 180 degrees of aim
Each pinna carries about 32 muscles. A human ear has 6 and manages perhaps 20 degrees of movement. A cat can swing each ear through roughly 180 degrees, aim the two independently, and hold both on a sound 10 m away. Horizontal angle comes from the 1–2 cm difference in arrival time between the ears; elevation comes from the folds of the pinna colouring the spectrum. This is how a cat tracks a moth at 1 m in near-darkness without moving its head.
The cost is energy. Each orienting response is a small arousal event, and a cat that fires 20 or more per hour is not curious, it is being audited by its environment. In a flat with a television at 65 dB(A), a fridge at 40 dB(A) and a neighbour's door at 95 dB(A), 30 or more startles an hour is easy to reach.
A household noise budget for one cat
| Source | Level at 1 m | Daily limit near a resting cat | What to do |
|---|---|---|---|
| Vacuum cleaner | 80–90 dB(A) | 2 min max, other room | Run it in another room with the door shut; leave 1 escape route |
| Blender | 85–90 dB(A) | 1 min max | Warn with 1 soft word, then start; cat leaves before the peak |
| Hair dryer | 75–85 dB(A) | 0 minutes within 1 m | Dry in a separate room, or switch to a towel and 20 minutes of air |
| Washing machine on spin | 65–75 dB(A) | 30 min, 2 m escape | Keep the laundry door open, not shut on the cat |
| Television or music | 60–70 dB(A) | 6 h or more | Cap at 65 dB(A); measure once with a phone app at the cat's bed |
| Dishwasher | 55–65 dB(A) | Full 90 min cycle | Acceptable; keep 1 quiet room under 50 dB(A) |
| Refrigerator hum | 35–45 dB(A) | 24 h | Ignore; this is the baseline your cat sleeps through |
| Door slam | 95–105 dB(A) | 3 events a day | Fit 4 felt pads per door; 2 seconds of work removes the peak |
Three numbers to hold: average 50 dB(A) or less in the sleeping room, peaks under 80 dB(A), and 8 hours a day below 50 dB(A). A cheap phone sound meter is accurate to about 3 dB(A), which is close enough to find the one appliance that is ruining the room.
Three hearing checks you can run at home
Jingle keys 2 m behind the cat at waist height, out of sight, and count to 10. Say the cat's name at 55 dB — ordinary room speech — from 3 m. Tap a spoon on a tin at 4 m on a hard floor. A cat that fails 2 of 3 is not being stubborn. Book an exam with an otoscope, and repeat the checks every 12 months after age 8. Deaf cats adapt well, but they need 2 changes: never touch them from behind at under 1 m, and keep 1 room mapped and unchanged.
What to change this week
- Move the vacuum to a room with a door, and shut it before you switch on. Target: 1 room the cat can reach in under 5 seconds.
- Add 4 felt pads to every interior door; a slam drops from 100 dB(A) to about 80 dB(A).
- Set the television to 60–65 dB(A) measured at the cat's bed, not at the sofa.
- Give the cat 3 vertical options at 40 cm, 90 cm and 150 cm so it can leave a loud floor without asking.
- Warm a wet meal to 30–38 °C during storm season; a warm bowl pulls a frightened cat back to routine faster than calling does.
If the fear is already generalised — hiding for 10 minutes after a doorbell, refusing food for 2 meals — read the posture signs that precede a panic and the storm-season noise plan. For how much age changes the picture, convert cat years before you assume the hearing is normal.
Frequently asked
Can cats hear a dog whistle?
Most dog whistles sit between 23 kHz and 45 kHz. A cat hears up to 85 kHz, so it can detect nearly all of them, while a dog with a 45 kHz ceiling hears only the lower end. If a cat ignores a whistle it is usually choosing to, not failing to hear it.
Is a vacuum cleaner actually painful for a cat?
It is rarely painful at 1 m, but it is startling: 80–90 dB(A) of broadband noise with strong energy at 20–40 kHz, plus a 5–10 dB(A) start-up surge. Most cats show stress within 30 seconds, so run it in another room.
Do cats lose hearing as they age?
Yes, and the top of the range goes first. High-frequency loss is common after 8 years, and a 12-year-old may hear only to 30–40 kHz. Run the keys, name and spoon checks every 12 months and book an otoscope exam if 2 of 3 fail.