SOUND KNOWLEDGE

These articles provide general sound knowledge and explore
sound - a phenomenon so common we rarely appreciate
all of its functions despite it touches nearly all areas of our lives.

Testing Futuristic Fighter Jets

Collaborating with Lockheed Martin for many years, Brüel & Kjær is supporting the demand for ‘right-first-time’ engineering and supplying reliable, high-quality, goal-focussed solutions for noise and vibration testing and analysis. This partnership is helping ensure the high performance of some of the most technologically sophisticated machines ever built.

Sound Intensity and Sound Power Relationship

Que sont la puissance acoustique et la pression acoustique ?

La puissance acoustique correspond à l’énergie sonore totale émise par une source acoustique par unité de temps. La pression acoustique est, en revanche, le résultat de l’émission d’énergie sonore par des sources qui rayonnent dans un environnement acoustique spécifique et est mesurée en un point précis. La puissance acoustique est la cause et la pression acoustique est l’effet.

Class-D technology: Enhancing sound quality

Class-D audio systems are the practical choice when you need more audio power.

The Longest Reverb

In 2014, acoustics expert Trevor Cox crawled through a narrow pipe into a subterranean oil tank in Inchindown, Scotland ...

Anatomie de l’oreille humaine

L’oreille humaine est un système complexe composé de trois parties distinctes, chacune jouant un rôle spécifique dans le processus de captage et d’analyse du son.

Cochlea Function - Ear Anatomy (Part 2/2)

In this second article on the anatomy of the human, we look at the process of transforming sound from mechanical vibrations into neurological signals. We take a closer look at the cochela, and the cochela function in relation to the hair cells located in the inner and outer ear that control our hearing sensitivity.

The Fauna Philharmonics

They howl, thump, bang, chirp and rumble. The sound and vibration repertoire of these animals would indeed make an interesting symphony.

What is Cavitation?

Cavitation is a primary source of propeller noise. The noise is caused by popping bubbles, sort of. They aren’t air bubbles, and they’re not actually popping. They are imploding bubbles of steam.   

Not so Long Ago in a Movie Right by You....

The sound of explosions, vehicles, weapons, rustling trees and even breathing – in one famous case – are carefully orchestrated elements that can make or break the audience’s immersion. But particular real-life noises might be kind of underwhelming, so where does that perfect sound come from?

Reigniting Guitar Evolution

In Spain, an aura of mysticism surrounds the construction of guitars, with the best concert-level instruments commanding enormous respect.

The Acoustic Properties Of A Ripe Watermelon

Many of our customers are engineers, and the different applications they explore outside the scope of their daily work are quite extraordinary.

Sound Art in Extremis: Mapping The Sound Ecology of Antarctic Weather

Sound artist and RMIT University academic, Dr Philip Samartzis, travelled to the Antarctic’s Casey Station as an Australian Antarctic Arts Fellow in early 2016, to explore the interaction of katabatic wind with the built and natural environments.

Fusing Form and Function In Room Acoustics

Keith Yates and his team have been engineering purpose-built director screening rooms and private theatres for 26 years, serving an international client base that ranges from well known directors, to private, unknown movie lovers.

AIISH - Developing Speech and Hearing

The All India Institute of Speech and Hearing (AIISH) develops methods for assessing and rehabilitating people with communication disorders all across India.

The Father of Dolby Technology

Learn about the pioneering legend who revolutionized the recording industry with Dolby Technology in this article.

Structure-borne Sound: Part 1

Previous articles covered the transmission of sound through air and how it is picked up by human hearing. This article addresses sound generation, particularly the vibration of solids and how that leads to sound – using an acoustic guitar as an example.

The Next Generation of Sound

Future challenges of electric vehicle noise control.

Savings in The Pipeline

According to the EU, one of our most promising untapped sources of renewable energy is the energy we can save by mitigating leakage and waste. Arne Jensen is at the forefront of harnessing wasted energy with his acoustic technology that detects and stops leakage in district heating systems – before it even begins.

Wavelength to Frequency, and the Speed of Sound

When you play music through a loudspeaker, the loudspeaker’s membrane is set in motion, alternately moving in and out. On its way out, the membrane compresses the air right in front; when moving back into the loudspeaker cabinet, it leaves more space for the air in front, causing it to rarefy.

Hemi-anechoic Chambers at The ARC

This year, the MSC Application Research Center (ARC) lab, located just outside Detroit, Michigan, celebrates its 10-year anniversary.

Something quiet this way comes

Traditionally pass-by noise measurement is a requirement for all automotive manufacturers as part of product certification, with measurement procedures defined in local and regional standards to ensure that noise levels are not exceeded, but times change. The introduction of extremely quiet electric vehicles (EVs) and hybrid vehicles (HVs) introduces more changes and challenges than just a different propulsion method; ‘too loud’ now only covers half of the problem.

Structure-borne Sound: Part 1

Exterior noise of a high-speed train

Transport by high-speed train is becoming more widespread particularly in these climate-conscious times. How can the external noise from these moving sources be efficiently measured and assessed?

My car. My engine. My sound

There’s not a cloud in the sky, and the empty highway beckons through your windshield. You nudge the pedal closer to the floor, and the roar of the engine feels like joy. But who decides how that roar sounds?

All quiet on board

Noise is a significant issue for anyone working on ships. Even moderate noise and vibration can affect comfort and lead to a drop in performance. Professor Hideyuki Shuri, an authority on ship noise, has been working for many years to overcome the challenges.

Predicting EV Warning Sounds

Electric vehicles (EVs) are so quiet at low speeds that they can be a danger to pedestrians, cyclists, and other road users. So the challenge for car manufacturers is to create sounds that are detectable but not annoying.

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