Shrillness is a word used to describe the quality of sounds that have a high-pitched, strident, raucous, screeching or harsh character, such as those produced by a
trumpet
The trumpet is a brass instrument commonly used in classical and jazz musical ensemble, ensembles. The trumpet group ranges from the piccolo trumpet—with the highest Register (music), register in the brass family—to the bass trumpet, pitche ...
or
piccolo
The piccolo ( ; ) is a smaller version of the western concert flute and a member of the woodwind family of musical instruments. Sometimes referred to as a "baby flute" or piccolo flute, the modern piccolo has the same type of fingerings as the ...
, but it can also be used to describe a widely recognised and puzzling phenomenon whereby certain sounds are perceived as psychologically painful or aversive to a degree that cannot be accounted for simply in terms of
frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio ...
content or
loudness
In acoustics, loudness is the subjectivity, subjective perception of sound pressure. More formally, it is defined as the "attribute of auditory sensation in terms of which sounds can be ordered on a scale extending from quiet to loud". The relat ...
. Such sounds include the
sound of fingernails scraping a chalkboard, the sound of chalk on a blackboard, the sound of glass being scratched, and possibly the sound of a
baby crying. There have been attempts to explain the phenomenon, often in terms of frequency content, or evolutionary advantage, but so far no complete explanation or mechanism has been found.
Research
A 2011 study by
musicologist
Musicology is the academic, research-based study of music, as opposed to musical composition or performance. Musicology research combines and intersects with many fields, including psychology, sociology, acoustics, neurology, natural sciences, f ...
s Michael Oehler and
Christoph Reuter has led its authors to hypothesize that the unpleasantness of the sound is caused by
acoustic resonance
Acoustic resonance is a phenomenon in which an acoustics, acoustic system amplifies sound waves whose frequency matches one of its own natural frequencies of vibration (its ''resonance frequencies'').
The term "acoustic resonance" is sometimes u ...
, as the shape of the human ear canal
amplifies certain frequencies, especially those in the range of 2000 to 4000 Hz (the median pitches), at such a level that the sound triggers pain in our ears.
References
{{Reflist
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