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How loud is a humpback whale song?

151–173dB re 1 µPa1 m (source level, back-calculated from at least 10 m)

The loudest units of a humpback whale's song have maximum source levels of 151 to 173 dB re 1 µPa, depending on the unit, measured by Au and colleagues in front of singing whales. That is well below blue, fin or sperm whales, but humpback songs are long, complex and rich in harmonics.

Level
151–173 dB re 1 µPadecibels relative to 1 micropascal, measured in water
Distance
1 m1 m (source level, back-calculated from at least 10 m)
Daily limit
Underwater levelnot an air level

What the numbers mean

How it was measured. Underwater level in dB re 1 µPa. Underwater decibels are not comparable with in-air decibels: see "underwater-vs-air". Maximum source levels of individual song units, 151 to 173 dB re 1 µPa, measured with a vertical hydrophone array at least 10 m in front of singing whales (Au et al. 2006).

Whitlow Au's team lowered a vertical array of five hydrophones in front of singing humpbacks, using snorkellers to check each whale's orientation and keeping at least 10 m away. The maximum source level varied between units of a song, from 151 to 173 dB re 1 µPa.

Harmonics extended beyond 24 kHz, the upper limit of the recorder, which the authors suggest means humpbacks may hear up to 24 kHz. The sound was projected horizontally even though singers hang head-down at anywhere from about 25 to 90 degrees.

Is it dangerous?

Measured in water against a 1 µPa reference, so the number cannot be compared directly with levels in air. See the underwater note on the Scroll. Marine-mammal and diver exposure criteria use their own metrics and are outside the scope of this page.

Protecting your hearing

No risk to swimmers. Keep the legal distance from whales for their sake, not your ears'.

Questions

How loud is a humpback whale?

The loudest units of humpback song measure 151 to 173 dB re 1 µPa at 1 m, depending on the unit.

Is a humpback louder than a blue whale?

No. Blue whale calls average about 189 dB re 1 µPa at 1 m, well above humpback song units.

Sources

  1. Acoustic properties of humpback whale songs, Journal of the Acoustical Society of America (Au et al., 2006) via PubMed. Supports: dB_low 151 / dB_high 173.The maximum source level varied between individual units in a song, with values between 151 and 173 dB re 1 microPaChecked 2026-11-02.
  2. Acoustic properties of humpback whale songs, Journal of the Acoustical Society of America (Au et al., 2006) via PubMed. Supports: Measurement distance.at a minimum standoff distance of at least 10 mChecked 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.