What is all the Noise About?

By Jim Thompson

Why do product noise control engineers get no respect?

I was recently in a meeting with several noise control engineers, and we were trying to define categories of noise control to be used in a website. I was surprised to find that no one suggested product noise control as one of the categories. When I stated that this category represented the highest number of noise control engineers, there was a lot of skepticism. This subsided when I noted there were roughly 1,000 product noise control engineers in the Detroit area just for the automotive industry.

This exchange made me think about product noise control engineers and how they are seen by others. Having served in this role, I know how difficult it can be. Even when the customer has specific noise/sound level requirements, the concept is to meet the noise goals without impacting any other aspect of product performance. For most product noise control engineers, preventing negative impacts on other aspects of product performance is as or more important than the noise reduction achieved. To distort an old phrase, product noise control engineers “get no respect”.

I can still remember when I was working for a tire company the product development chief engineer came to me to request a noise reduction in a new tire for an original customer (OE), like GM, Ford, or Toyota. We went over where he was in the tire development process and the sign-off status with the customer. I summarized this discussion by saying what he wanted was a 3 dB reduction in noise while not changing the tread design or the tire construction and not impacting any of the other aspects of tire performance. The chief engineer completely agreed with me and did not understand why I was laughing so hard. Oh, and by the way, we did achieve his goals with small changes to the tread design that did not adversely affect other aspects of performance.

As a consultant, I was often asked in to improve the noise performance of a product after the company’s product noise control engineers told management they could not meet the sound level goals without making significant changes to the product. In my most successful projects, I built a good relationship with the company’s product noise control engineers, and we worked together to demonstrate the need for the changes and sometimes disguised them as product improvements. As a consultant, we automatically got more respect than the internal product noise control engineers.

Noise control engineers who have not been in this position do not realize how tough it is for the product noise control engineer. Many times, good noise controls are ruled out for cost or performance impact reasons before the process starts. Too often, I have seen consultants come in and recommend measures that were rejected when proposed by the in-house expert and receive a positive reception. As I said, product noise control engineers get no respect.

I would like to hear your stories as product noise control engineers. What are the problems you encounter? Have you experienced consultant recommendations being received in a different light than yours? What have you done to grow respect and help others to understand the limitations to the “magic” you can apply to solve noise problems?