Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Ear Anatomy May Amplify Irritating Tones of Chalkboard Squeak

The sound of fingernails on a chalkboard sets many people’s teeth on edge, and now a team of researchers from the University of Cologne in Germany and the University of Vienna in Austria think they know why.

In a study designed to pinpoint the source of this and similarly irritating sounds, scientists found that the most obnoxious elements of the noises may be amplified by the shape of the human ear. The team will present its results at the 162nd meeting of the Acoustical Society of America (ASA), which runs from Oct. 31 – Nov. 4 in San Diego, Calif.

In the study, scientists removed information from actual audio clips of people scraping their nails or bits of chalk against a chalkboard. They then played these modified clips to willing participants. Half the study subjects were told what the sounds were; the other half thought that they were listening to selections from contemporary music. Scientists asked the participants to rate each sound’s unpleasantness, and also gauged the subjects’ stress responses to the noises by measuring their blood pressure, heart rate, and skin conductivity (a measure of sweating).

The human ear is known to be particularly sensitive to pitches in the mid- to low-level range of frequencies, between 2000 hertz and 4000 hertz, which is the peak of human hearing. It turns out that when scientists removed all the pitch information in this range from the audio recordings, the study participants rated the noises as more pleasant than other versions of the sounds. One explanation for people’s sensitivity to this band of frequencies is that sounds in this range are amplified due to the anatomy of the ear canal; they are literally louder to us than other sounds are. So chalkboard squeak may be irksome because the most obnoxious elements of the sound sit right in the sweet spot of human hearing.

... more about:
»Acoustical Society »Amplify »Chalkboard »EAR »Squeak

“We supposed that frequencies in the low-mid range [of human hearing] would play a major role” in the unpleasantness of the sounds, said Michael Oehler, professor of media and music management at the University of Cologne in Germany, who will present his team’s findings at the conference. “But we did not know the exact range. Furthermore, the influence of pitch information was greater than we thought.”

Of potential interest to psychologists is the finding that participants who knew that the sounds they were hearing came from nails on a chalkboard rated these sounds more unpleasant, and experienced a higher degree of sweating, than the people who thought they were listening to music.

The presentation, “Psychoacoustics of chalkboard squeaking,” by Christoph Reuter and Michael Oehler will be at 3:15 p.m. on Thursday, Nov. 3 at the Town and Country Hotel and Convention Center in San Diego, Calif.

Main meeting website:
Searchable index:
Hotel site:
Webcast registration and viewing:
In the week before the meeting, the ASA's World Wide Press Room ( will be updated with lay-language papers, which are 300-1200 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio, and video.
The Acoustical Society will grant free registration to credentialed full-time journalists and professional freelance journalists working on assignment for major news outlets. If you are a reporter and would like to attend, contact Charles E. Blue (, 301-209-3091), who can also help with setting up interviews and obtaining images, sound clips, or background information.
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world's leading journal on acoustics), Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. For more information about ASA, visit our website at

Charles E. Blue | Newswise Science News
Further information:

Further reports about: Acoustical Society Amplify Chalkboard EAR Squeak

More articles from Physics and Astronomy:

nachricht OU-led team discovers rare, newborn tri-star system using ALMA
27.10.2016 | University of Oklahoma

nachricht First results of NSTX-U research operations
26.10.2016 | DOE/Princeton Plasma Physics Laboratory

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>