Silentium is the Latin word for silence.  

For Yossi Barath it represents a calling – his goal is to create a quieter world, a world in which the noise pollution associated with modern life is minimized, if not entirely eliminated.  Which is why, after more than 20 years as an executive with the Israeli company Elbit and a scant six months of retirement, in 1999 he returned to the business world as the CEO of a startup named – you guessed it – Silentium.

From range hoods to data center servers, Silentium has helped its OEM customers quiet their products by incorporating its unique active noise control (ANC) solutions – what the company calls “silence in a chip.”

Barath says that Silentium has developed very smart ANC algorithms that use an “anti-noise” signal – a mirror image of the original signal –that interferes with the original sound and cancels it out.  He points out that this principle of destructive interference is not new. It’s just that Silentium found a practical way of using this basic principle of physics to create a small, low-cost highly effective solution that has a number of advantages when compared to traditional passive noise reduction methods that use foam and barriers.  

For example, Barath explains, when passive components are used as a sealing material, they block airflow paths and disrupt the performance of the device they are insulating.  “Active noise control is ideal for products in the ventilation area and for anything else that has to do with air flow,” he says.  

Passive systems are very effective at high frequencies – 1000 Hz and above.  But ventilation systems, such as range and cooker hoods, produce much of their noise energy in frequencies below 1000 Hz.  The Silentium solutions, unlike other ANC systems, extend the low frequency range of signals up to 1800Hz while allowing an undisturbed airflow path. The company’s proprietary algorithms allow the ANC product to achieve noise reductions of about 10 dB(A).

In addition to helping manufacturers make a quieter product, the Silentium solution lets them adjust the quality of the sound that is being emitted – even an almost inaudible sound can have characteristics that set your teeth on edge.

Helping Faber Stay Out in Front
Appliance manufacturers are particularly interested in noise control.  For the past several years, Silentium has been working closely with Faber, the Italian company that invented the range hood in 1955.  

Now, some 50 plus years later, Faber is a global manufacturing company with production facilities or offices in seven countries and range hoods selling in every major market around the globe.  Even though they have an enviable 50 percent market share, competition in the range hood market is fierce.  So, the company is constantly on the lookout for an advantage. Incorporating ANC technology in the form of the Silentium chip is one of the ways it can stay ahead of its competitors.

In most range hoods, the blower that is typically used to move air through the system is the greatest source of noise.  Like other typical air moving devices, the range hood consists of an air inlet, air outlet and body – also sources of noise.  Complicating matters is the fact that each of these components has its own noise levels, spectra, and characteristic air flow paths.

In 2007, recalls Samuel Riitano, Director of Operations for Faber SpA, they were concentrating on using passive technology to develop the most silent cooker in the world.  Their efforts allowed them to devise a solution that matched the results their competitors were achieving with their passive technologies.  “But we wanted to do better; we needed some exciting results,” says Riitano.

Faber decided to investigate active noise control technology.  “ANC not something new, but the difficulty was to find a solution that really worked in the product and the manufacturing process, not just in the laboratory,” Riitano recalls.  “So we looked for partners.”

In 2007 they found an ANC supplier, but after six months of work it became apparent that they were moving down the wrong track. The vendor’s solution involved electronics that were the size of a desk and could not be integrated into Faber’s products.  

Fortunately, they quickly found Silentium, which was already providing small, efficient ANC solutions for data center servers.  “From the first meeting it was clear that we had found the right partner to work with,” says Riitano.

The two companies formed a partnership agreement and together began working on solutions that would provide the level of noise abatement Faber wanted without compromising airflow.  This included operating the potential new products over a wide range of severe environments such as high temperatures, humidity and exposure to grease.  

Faber and Silentium engineers relied heavily on computational fluid dynamics (CFD) modeling and simulation software from ANSYS Fluent to test new blower designs without making a series of expensive and time-consuming physical prototypes.

Engineers at both companies were trained at Silentium workshops on how to embed the ANC chips into the Faber products to optimize the solution.

Even with the use of advanced digital manufacturing techniques such as CFD, it took time to find a solution that not only provided cutting-edge ANC technology but also delivered price/performance specifications that would move Faber decisively out in front of its competition.

Based on a solid backlog of virtual simulations, the final prototype was built in 2011 and shown to a select group of Faber customer who responded with great excitement to the direction the company was taking.  The Faber products featuring the ANC technology will be launched in mid-July of this year.  Says Riitano, “We are very proud to be the first company in the world to introduce real products in white appliances using active noise cancellation.  We have achieved our goal of creating the most silent range and cooker hoods in the world today.”

For both Faber and Silentium another Latin phrase seems very appropriate: Silentium est aureum, which translates as “silence is golden.”