NVH & Audio System Benchmarking

In this blog post, we are going to discuss the NVH and Audio System benchmarking services offered by ARC to our automotive clients.

Benchmarking effectively allows us to objectively characterise the acoustic performance of a vehicle, this data can then be used to develop targets for future vehicles – ensuring that the acoustic performance is comparable or better to competitors or existing products.

At ARC, we offer a full suite of NVH benchmarking services. The most common NVH attributes to be assessed are:

• Wind Noise
• Road Noise
• Powertrain Noise & Vibration
• Ride Comfort
• Cabin Ancillary Systems
• HVAC Noise
• Squeak & Rattle
• Audio Systems

In most cases, the noise (and vibration performance, where applicable) is measured under defined conditions, such as road speed, engine speed, load etc.

Each NVH attribute will require a different post-processing and reporting method, along with various acoustic metrics used to quantify each. For example, stationary, broadband acoustic signals such as wind noise and HVAC noise can be easily analysed using a time-averaged frequency spectrum (such as an FFT or octave-band analysis), overall SPL levels and some psychoacoustic metrics such as Articulation Index.

Time varying, dynamic signals may require some more advanced analysis methods. For example, powertrain noise and vibration (during a runup or coast-down) can be analysed using order tracking methods, in order to take into account the varying source frequency / RPM.

Finally, systems which are more sensitive to human perception, such as cabin ancillary systems which are used often by vehicle occupants, will require additional psychoacoustic analysis. This is required to characterise not just the noise and vibration levels of these systems, but also the sound quality performance. In many cases, the noise level is less critical than the actual sound of these systems.

Over the next few months, ARC will be publishing high-level summaries of some of the NVH Benchmarking which has been completed on current production vehicles. Keep an eye on the blog for further updates.

If you feel that our NVH engineering services can be of assistance to your company, then please feel free to get in touch.