Some of the most significant examples of this phenomenon exist in the automotive industry, where the Acoustic Camera has already been in use with great success. Rattling, hissing, or clicking noises are undesired in any vehicle. Even at high speed, the pianissimo parts of classic music should not be drowned out by driving noise.
Shutting the door, however, must produce a full sound despite the lightweight construction. There are similar requirements for the sound of car engines. The roar of a sports car or the sonorous sound of a Sedan are typical distinctive characteristics of car brands. That's why big effort goes into modelling the desired sound and into eliminating disturbances.
Sound issues are playing an increasingly important role in household appliances. Some high-value products can already be identified by their "high-value sound". Noises that are usually associated with faults like clicking, crackling, or whistling can cause annoyance for customers and frequently lead to unnecessary complaints
The time, frequency and modal analyses used so far have a decisive disadvantage: the spatial resolution is limited or non-existent. If you want to record many locations of the machine at the same time, you need a separate microphone for each measuring point, which has to be placed close to the measuring object - a high financial and time expenditure.