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The Quiet Forefront PUBLIC ACCESS

Consumer Electronics Makers are Putting Acoustical Analysis into the Hands of Design Engineers to get Noise out of Products Earlier

[+] Author Notes

Jean Thilmany is an associate editor of Mechanical Engineering magazine.

Mechanical Engineering 136(08), 44-49 (Aug 01, 2014) (6 pages) Paper No: ME-14-AUG3; doi: 10.1115/8.2014-Aug-3

This article highlights the acoustical analysis changes made by manufacturers in design cycle. Acoustical simulation is being pushed from experts to designers, following the trend for the last 15 or so years that saw other types of engineering applications like finite element analysis and computational fluid dynamics become integrated with computer-aided design packages used by mechanical engineers. With the advent of software packages that allow for design and for acoustical analysis in tandem, design engineers are increasingly running these analyses early in the development cycle and are making design changes to decrease noise and vibration issues they find. Experts suggest that with speaker sound quality and other pertinent information in hand, designers can actually design from the get-go with that information in mind, resulting in fewer design changes down the line. Though early acoustical simulation is still perhaps one of the consumer electronics’ industries best-kept secrets, that’s likely to change as word gets out about the many advantages of front-line simulation.

In the past, those concerns were analyzed and treated after a product was designed, passing down the line from design and mechanical engineers to acoustics analysts. Today, manufacturers are increasingly bringing acoustical analysis into play earlier in the design cycle. Indeed, they are putting that power into the hands of the design engineers.

Grahic Jump LocationIn the past, those concerns were analyzed and treated after a product was designed, passing down the line from design and mechanical engineers to acoustics analysts. Today, manufacturers are increasingly bringing acoustical analysis into play earlier in the design cycle. Indeed, they are putting that power into the hands of the design engineers.

We are told this by makers of acoustic analysis software. It seems that this kind of analysis is so new to their industry that consumer electronics manufacturers treat it almost as a trade secret. None that we approached would agree to be interviewed for this article.

Acoustics was previously “in the nice to have” category for those manufacturers, said Ruben Bons, manager for business development in the electronics sector at CD-adapco. The company, based in Melville, N.Y., makes Star-CCM+, which can be used for acoustical analysis.

“It was something the electronics people thought about, but as design priorities go it wasn’t first or even a second item,” Bons said. “But I’ve been noticing in certain industries that priority is moving up quickly.”

Acoustical simulation is being pushed from experts to designers, following the trend for the last 15 or so years that saw other types of engineering applications like finite element analysis and computational fluid dynamics become integrated with computer-aided design packages used by mechanical engineers.

Bringing acoustical analysis to front-end design helps reduce a product's time to market and, at the same time, cuts extraneous noise from consumer electronics, said David Burd, manager of engineering at MSC Software in Newport Beach, Calif. MSC makes Actran Acoustics.

According to Burd, in the design process of the recent past, industrial and mechanical engineers received sets of requirements for what a product must be able to do. They designed a device to meet those specifications and then sent the design over to what was often an ad hoc acoustics team to fix acoustical issues. Many of the acoustics analysts had come to their jobs by way of earlier engineering jobs coupled with on-the-job training.

“Televisions, cell phones, the compressors on refrigerators—these are all things that have acoustics issues,” Burd said. “But in those industries, acoustics has been an afterthought.”

But with the advent of software packages that allow for design and for acoustical analysis in tandem, design engineers are increasingly running these analyses early in the development cycle and are making design changes to decrease noise and vibration issues they find.

Because automotive and aerospace makers commonly run acoustical analyses, “their competitors know they’re doing these analyses. It's no big deal,” according to Bons of CD-adapco. “In electronics they’re still looking at acoustics as a competitive advantage.”

Some of the recent emphasis on earlier acoustical analysis is prompted by regulatory concerns. The European Telecommunications Standard Institute and the Network Equipment Building System guidelines in the United States both are beginning to include some noise specifications, Bons said, although they apply only to the telecommunications industry.

For the makers of consumer electronics, the wider move to bring acoustical analysis to the front is an effort to design more efficient devices and to woo potential buyers, Bons said.

Noise or vibration could alert the manufacturer of underlying issues or inefficiencies within a product's operating system. “More noise means less efficient,” he said.

And a great deal of the emphasis on how a product sounds as it operates comes about because consumers will associate noise and vibration with poor product performance. They’re more likely to seek out quiet products in a hypercompetitive industry, Bons said.

“With electronics, it's the impression of quality,” he said. “If you can hear the laptop, you’re on the undesirable side of quality.

“It's not a new concern, but I’ve been noticing the visibility and priority of concerns about acoustics are growing,” he added.

Because acoustical analysis followed the design stage, it sometimes resulted in sending the product back for adjustments—and design cycle time suffered. Or the sound quality itself suffered if the product was ushered out the door on time.

Noise or vibration could alert the manufacturer of underlying issues or inefficiencies within a product's operating system. A great deal of the emphasis on how a product sounds as it operates comes about because consumers will associate noise and vibration with poor product performance. They’re more likely to seek out quiet products in a hypercompetitive industry.

Grahic Jump LocationNoise or vibration could alert the manufacturer of underlying issues or inefficiencies within a product's operating system. A great deal of the emphasis on how a product sounds as it operates comes about because consumers will associate noise and vibration with poor product performance. They’re more likely to seek out quiet products in a hypercompetitive industry.

Consumer electronics makers know they need to look at acoustical issues at the place where the electronics and the mechanics and the physical body of the device come together, which is often the purview of design engineers, said Sudhir Sharma, director of high-tech industry strategy at ANSYS in Canonsburg, Pa.

“They have to look at the intersection of all these physics,” Sharma said.

No more noise

Mechanical engineers, working with industrial engineers, can use the software to predict a device's pattern of sound radiation, sound quality, loudness, and how the components inside will contribute to overall sound through vibration, Burd said. In the same way that they can simulate assemblies, subassemblies, or components with CAD in tandem with engineering software, engineers can perform either component-level or system level noise and vibration analyses while they design, he added.

Take the example of a cell phone.

According to Burd at MSC, “An engineer would have the geometry for a cell phone in CAD and then they’ll take the speaker they want, put the simulation of that speaker inside the CAD simulation, fit it together in CAD, and put it into the acoustics software and work on sound performance. All within a virtual prototype.”

Often the speakers used in consumer electronics are purchased from suppliers who provide speaker parameters, such as loudness and tone, for the design engineer. The speaker can then be simulated inside a cell phone housing that exists only in the form of a CAD file, he added.

If the predicted sound quality doesn’t meet specifications, the design engineer can change the CAD model to decrease vibrations or unwanted noise, or can choose another speaker, Burd said.

Screen images depict acoustical analyses for gearbox noise, simulated in Actran Acoustics from MSC Software. The developer has found consumer electronics engineers are increasingly using the application to explore acoustical issues the early stages of design.

Grahic Jump LocationScreen images depict acoustical analyses for gearbox noise, simulated in Actran Acoustics from MSC Software. The developer has found consumer electronics engineers are increasingly using the application to explore acoustical issues the early stages of design.

What's changed is the accessibility that allows expert tools to be used by a mechanical engineer or designer because those tools become easy enough to use and understand.

Design engineers have the geometry of a cell phone in their CAD system. They can take sound parameters for the speaker, simulate the speaker in the software, and compute an acoustical analysis.

Grahic Jump LocationDesign engineers have the geometry of a cell phone in their CAD system. They can take sound parameters for the speaker, simulate the speaker in the software, and compute an acoustical analysis.

All this means that software makers are now coupling or integrating acoustical analysis software with the CAD software used by mechanical engineers or are customizing their software for a manufacturer to perform acoustical analysis earlier in the design cycle.

“What's changed is the accessibility that allows expert tools to be used by a mechanical engineer or designer because they’ve become easy enough to use and understand,” Sharma said.

MSC Software recently worked with, Oticon, a Somerset, N.J., maker of hearing aids, which recently gave designers responsibility for initial acoustical simulation, Sharma said. ANSYS customized its Application Customization Toolkit, or ACT, software for Oticon users.

“I’ve known them for the past six years, and there were only experts doing acoustics,” Sharma said. “Two years ago, they started on a project to make it easier for designers to do acoustics simulation. We helped them make the tools easier for everyone.”

The hearing-aid maker knew that to stay ahead of its competition, it needed to simulate all the components that interacted rather than only the key parts of the hearing aid, said Martin Larsen, Oticon's simulation specialist.

Hearing aid manufacturer Oticon knew that to stay ahead of its competition it needed to simulate all the components that interacted in its product. A model of the assembled parts is shown here.

Grahic Jump LocationHearing aid manufacturer Oticon knew that to stay ahead of its competition it needed to simulate all the components that interacted in its product. A model of the assembled parts is shown here.

With the software, Oticon hoped to evaluate more design options in a shorter amount of time than in the past, use simulation to create a more reliable product, and reduce cost and time to market by minimizing troubleshooting later in the design process.

With the software, Oticon hoped to evaluate more design options in a shorter amount of time than in the past, use simulation to create a more reliable product, and reduce cost and time to market by minimizing troubleshooting later in the design process, he added.

Oticon used the ACT software to simplify the creation of models for microphones and receivers. The hearing-aid maker also created workflows that walked the designers through the process of simulating device performance, Larsen said.

Now, Oticon designers do 75 percent of design validation formerly done by simulation experts. This allows the experts to focus on the sensitivity of the device and to better understand potential failures, Larsen added.

Earlier simulation also allows designers to order speakers earlier in the design process, Burd said. Usually, a manufacturer orders the speakers for devices such as cell phones or stereos from suppliers, and often, Burd said, the speakers are first tested in the prototyped device itself.

But with speaker sound quality and other pertinent information in hand, designers can actually design from the get-go with that information in mind, resulting in fewer design changes down the line, he added.

Though early acoustical simulation is still perhaps one of the consumer electronics’ industries best-kept secrets, that's likely to change as word gets out about the many advantages of front-line simulation, Burd said.

According to Burd, “Electronics is a very strong and growing industry, and most people within it could benefit from acoustic simulation.”

Copyright © 2014 by ASME
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