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How loud is the water boatman?

78.9–99.2dB peak1 m (estimated, underwater)

The water boatman Micronecta scholtzi, an aquatic insect a few millimetres long, sings underwater at an estimated 78.9 dB (rms) with peaks of 99.2 dB, scaled to 1 m and expressed relative to 20 µPa. Sueur and colleagues (2011) found it the most extreme outlier for loudness relative to body size among 228 species compared.

Level
78.9–99.2 dB peakunweighted peak sound pressure level
Distance
1 m1 m (estimated, underwater)
Daily limit
Impulse below 140 dB peakimpulse noise

What the numbers mean

How it was measured. Calling song of male Micronecta scholtzi recorded underwater with a hydrophone in tanks, converted to dB re 20 µPa (the air reference, for comparison with land animals) and estimated at 1 m (Sueur et al. 2011). 78.9 dB is the average rms level, 99.2 dB the average peak, for the median distance estimate.

Males make the sound by rubbing a tiny ridged area on the genitalia against the abdomen, a structure no more than 50 µm long. Sueur and colleagues recorded the insects in tanks with a hydrophone and, because the exact distance to each insect was unknown, estimated the level at 1 m for minimum, median and maximum distances. The median estimate gives 78.9 dB rms and a peak of 99.2 dB re 20 µPa.

Scaled to body length and compared with 227 other species, the water boatman came out as an extreme value, ahead of marine and land mammals. The authors note that the song can be heard by a person standing at the side of a pond or river, even though it is produced underwater.

The comparison needs care. The authors point out that producing loud sound underwater is easier than in air, and underwater levels are normally quoted relative to 1 µPa rather than 20 µPa, which makes the same pressure read about 26 dB higher. Very little of the sound crosses into the air.

How dangerous is a 78.9–99.2 dB peak?

Peaks of 78.9–99.2 dB stay under the 140 dB impulse limit, but repeated impulses add to the daily dose and the UK and EU action values start at a 135 dB(C) peak.

RulePeak limitThis sound
UK and EU lower exposure action value135 dB(C)Below
UK and EU upper exposure action value137 dB(C)Below
UK and EU exposure limit value; NIOSH and OSHA impulse ceiling140 dBBelow

Protecting your hearing

No risk to people: almost all of the sound stays in the water.

Earplug and earmuff ratings (NRR in the US, SNR in the UK and EU) are lab figures; real-world protection is usually lower. How to read the ratings.

Questions

What is the loudest animal for its size?

Sueur and colleagues (2011) found the water boatman Micronecta scholtzi to be the most extreme outlier for loudness relative to body size among 228 species compared, with peaks of about 99.2 dB at 1 m.

Can you hear a water boatman?

Yes. The study reports that its song can be heard by a human from the side of a pond or river.

Is it really as loud as a jackhammer?

Not in air. The figures were measured underwater and then expressed relative to 20 µPa; very little of the sound crosses into the air.

Sources

  1. So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae), PLoS ONE (Sueur et al., 2011). Supports: dB_low: 78.9 dB rms at 1 m.Sound is produced at 78.9 (63.6–82.2) SPL rmsChecked 2026-11-02.
  2. So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae), PLoS ONE (Sueur et al., 2011). Supports: dB_high: 99.2 dB peak at 1 m.with a peak at 99.2 (85.7–104.6) SPLChecked 2026-11-02.
  3. So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae), PLoS ONE (Sueur et al., 2011). Supports: summary: peaks around 100 dB.When considering peak values, i.e. the loudest part of signal, the intensity can reach 100 dB SPL.Checked 2026-11-02.
  4. So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae), PLoS ONE (Sueur et al., 2011). Supports: body/faq: audible from the bank.The song can be heard by a human ear from the side of a pond or river, propagating across the water-air interface.Checked 2026-11-02.
  5. So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae), PLoS ONE (Sueur et al., 2011). Supports: body: underwater caveat.Producing loud sound underwater is easier than in the air due to impedance-matchingChecked 2026-11-02.
  6. So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae), PLoS ONE (Sueur et al., 2011). Supports: body: 50 µm stridulatory apparatus.This sound emission system does not measure more than 50 µm in lengthChecked 2026-11-02.
  7. So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae), PLoS ONE (Sueur et al., 2011), via PubMed. Supports: dB_high: 99.2 dB peak.with a peak at 99.2 (85.7-104.6) SPLChecked 2026-11-02.
  8. So small, so loud: extremely high sound pressure level from a pygmy aquatic insect (Corixidae, Micronectinae), PLoS ONE (Sueur et al., 2011). Supports: summary/line: a few millimetres long.This insect is a few millimetres in length yet can produce sound audible from the riverside.Checked 2026-11-02.

This page is general information, not medical advice. If you have ringing in your ears, muffled hearing or any change in your hearing, see an audiologist or your doctor.