Sound Quality for Consumer Products

Optimisation of Sound Quality has become an increasingly important activity in the design and development of all products that emit noise, for example, automobiles, trains, aeroplanes and all kinds of household appliances.

There are two distinct reasons for optimising sound quality – firstly, to optimise the sound to satisfy the specific customer group; secondly, to increase the product’s competitiveness and sales. Most products include a variety of individual components from different sub-suppliers. These must satisfy quality requirements including those for sound performance.

The optimisation process involves the following steps:

• Recording of sounds on site, for examples, in a car on a test track using a Head and Torso Simulator (HATS)
• Analysing the sounds in a laboratory using both traditional methods and specific objective metrics such as Zwicker Loudness 
• Simulating changes in the sounds using a number of edits 
• Preparing and conducting subjective listening tests 
• Creating product-specific Combination Metrics to cut development time and cost

Brüel & Kjær offers complete systems from the simplest to the most advanced.  

	There are 18 different ways to edit or modify sound signals. The real-time filter tool uses IIR filters. After a parameter change you can immediately listen to the change in sound by just using the cursor
	With the Zwicker Loudness option a large number of metrics can be calculated and displayed. Here you see a non-stationary Loudness contour plot, a graph showing Total Loudness vs. Time and a table of calculated Metrics