Accuracy vs. Realism: Simulating The “Human” Side Of Audio Measurement

Although sometimes overseen, out auditory system has two inputs… Our left and right ears. This system that is responsible for our ability to locate sounds is called binaural.  According to some, playback systems may include upwards of 5 speakers while 2 will do fine recreating what we hear naturally. For years stereo mics have been used to capture sounds that simulate space and realism, which add depth to recordings. Acoustic measurement systems benefit from these because they keep the human characteristic.

While performing acoustic measurements there are two things to be considered, accuracy and realism.  This means we will have to choose between what is going on scientifically and what is being perceived by the human brain.

There are 2 factors in acoustic measurement the humans response ,which is constant, and the loudspeakers response , which can be position dependent but does not have to be.

Choosing whether accuracy or realism is more important comes down to purpose. If you are trying to calibrate an EQ or crossover then accuracy is more important. If you were trying to know what a room sounds like then realism is more important.

Mic placement when trying to achieve realism is much easier. The user simply places the mics in a spot where they would typically be listening. One of the most common mic techniques used is X/Y and more often than not this produces a convincing stereo image.  Another technique used is two spaced omnidirectional mics.  It is important to remember that all of this is relative and it all comes down to what you like, there are not rights or wrongs.   

Those looking for increased realism can opt for using a “head”.  It is not uncommon to use  Head Related Transfer Function (HRTF) by having an absorptive mass between the two mics.

Premade “heads” can  be purchased through some mic manufacturers but their price can prove impractical to some that will not be able to justify the high cost. Other alternatives exist like using your own head.  The In the Ear technique (ITE) was pioneered by Don and Carolyn Davis in the 1980’s.  The technique captures outer ear response by placing mics at the surface of ones ear.  A variation of this called the At the Ear increased practicality by placing mics at the entrance of the ear.

While a lot of measurements can be gathered it is essentially up to you to decide the perspective needed. The use of many techniques can provide insight as to what is going on both accurately and realistically.

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