The blackbird proved to be the most melodious singer amongst 123 species of bird

The song of the blackbird received the highest rating in an experiment involving the calls of 123 bird species found in Germany. The tawny owl came last: participants found its shrill cries the least pleasant.

People tended to prefer soft, varied sounds with a relatively high pitch, but without too wide a range of frequencies. However, the ability to recognise birds by their appearance or song did not influence the ratings.

Details

The study was conducted by a team from the University of Tübingen. The research was published in the peer-reviewed journal *Frontiers in Bird Science*.

The experiment involved 84 adults aged between 19 and 81. In the laboratory, they were played 15-second recordings of the calls of 123 European bird species through identical headphones. The names of the species were not disclosed, and the order of the recordings was randomised. Each recording had to be rated on a scale of one to five.

The average rating across all species was 3.13 points. The blackbird scored 4.52 points, whilst the tawny owl scored 1.32 points.

The researchers then measured the volume, pitch, frequency range and complexity of each clip. Complexity here was defined as the number of different types of sound elements, rather than simply the number of repetitions.

The participants found varied but comparatively quiet calls more pleasant. They also preferred recordings with a higher fundamental frequency and a narrower frequency range — that is, without abrupt transitions between very low and very high sounds. The sheer number of individual sounds in a 15-second period did not play a significant role.

People who generally had a positive attitude towards birds gave higher ratings. However, experience of birdwatching and the ability to recognise species by their calls did not show a statistically significant correlation with the ratings.

For 21 species, the researchers also compared the results with an earlier study on the restorative effects of nature sounds. The pleasantness of the call and the perceived ability to aid recovery from stress were linked, but this was merely a correlation: the new experiment did not measure any actual reduction in stress or improvement in well-being.

Why this is important

The study helps to provide a more precise understanding of what constitutes a natural soundscape that is pleasant to humans. In future, such data may prove useful when studying city parks, recreational areas and other places where the acoustic environment influences the perception of space.

However, it is too early to turn the results into a ready-made guide to landscaping. The study was conducted in a laboratory, not in a real park or forest. It involved only 84 adults from a single cultural background, 61 of whom were women. The authors also used just one short clip for each species and did not take into account how often a bird repeats its calls or songs.

Vocal complexity was assessed solely on the basis of the number of distinct elements — without taking into account rhythm, predictability or other characteristics. Therefore, the findings cannot automatically be applied to people in other countries or regarded as a universal ranking of birds.

The authors suggest that soft and varied voices may be associated by people with a safe and healthy natural environment. However, the experiment itself did not test this possible explanation and does not prove that a preference for certain sounds is biologically ‘hard-wired’ into humans.

Source

1. Phys.org: “Scientists discover the key ingredients that make birdsong pretty”, 2 September 2026.
2. Nadine Kalb et al. “Analyzing the acoustic parameters of bird vocalizations and their perceived pleasantness by humans”, Frontiers in Bird Science, 2 September 2026. DOI: 10.3389/fbirs.2026.1794594.
3. Frontiers press release on the study, 2 September 2026.

Photo: Balazs Szanto. Source: Frontiers. Licence: CC BY-SA 2.0; the image has been cropped and is distributed under the same terms.