Study Hall

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Whistle While You Work: Using Your Body As An Ultra-Low-Tech Test & Measurement Instrument

A guide to your "on-board kit" and how it can make your work a little quicker and easier...

Next: After a few short exchanges, the person facing the stage backs up by about five paces, while the conversation continues. Again, after a few short exchanges, the same person moves back another five paces. Continue this process of talking and moving apart until you reach a point at which the conversation becomes either unintelligible or nearly inaudible.

If you begin experiencing lower and lower intelligibility, before reaching the physical limits of the space, you’re most likely at or beyond the point of critical distance. This means you’re hearing more reverberant energy than direct sound from the other talker.

Presuming you haven’t reached critical distance as you move further and further apart, you may find a point where the other person’s voice is just too soft to be easily heard. If this happens, it’s an indication that a sound reinforcement system may be needed to amplify the spoken word. If neither scenario occurs, you’re probably evaluating a fairly small room or one with reasonably good acoustics.

Let’s Test Our Hearing

Ever noticed that your hearing seems a little “off” some days – especially in the mid-frequency range and above – but you aren’t sure what’s changed? (Me too.) Here’s a simple trick: While holding a hand close to either ear, rub your thumb, index and middle fingers together. The friction of your fingerprints will cause a soft, mid- and high-frequency “white” noise reference signal. (See Figure 2.)

Figure 2: Frequency spectrum of the palms of my hands when rubbed together, via the Spectrum Analyzer phone app by Raspberrywood. The red line represents the peak energy graph when rubbing my hands together, and the green line represents the ambient noise level in my office. The bandwidth between 1 kHz and 8 kHz is surprisingly flat.

Does this noise sound the same in both ears? If so, that’s good. If not, there’s a chance you have excess wax in one ear, a Eustachian tube blockage due to illness, a temporary hearing loss due to overexposure to high SPLs, or possibly some permanent hearing loss.

It’s a good idea to get familiar with this sound when your ears are clear and rested. Then, when you feel the need to check, you can cross check what you may be hearing from your favorite reference tracks, against what the fingerprint friction test reveals. I’m not suggesting this takes the place of a proper hearing test, administered by and audiologist, but rather another trick in the tool bag, when you feel the need.

Here’s a minor variation for any of the older folks out there whose fingerprints have worn smooth. The same process works if you rub the palms of your hands together next to an ear. More surface area means a little higher SPL, but similar tonality.

A Matter Of Trust

Do you trust your ears? Are you an “active” listener, and have you begun to develop and refine your mental library of sounds? (For more on this, check out “The Mental Side Of Mixing.”)

If you don’t already, you need learn to trust your ears. With first impressions, and even after a more thorough analysis, they should give you a very reliable take on how things are working and sounding.

For example, when compared to an unamplified, face-to-face conversation, does the human voice you’re listening to sound natural when amplified through the local system? If not, do you really need to bring in a dual FFT analysis program to confirm there’s a problem? I think not.

The computer rig may confirm the problem by showing you specific frequency and phase anomalies, but it won’t tell you what’s causing the problem. With today’s test and measurement tools, there are many highly sophisticated options to help refine and verify a system’s performance. But overall, our ears should be the first, then final arbiter of a system’s quality and performance.

Final Thoughts

I realize there are many phone apps and laser measuring devices that can take the place of my “organic” tools. They’re easy and obvious.

But it’s my hope that you find at least one or two of the tips presented to be worth considering for those times when you have no cell service, have left your specialized electronics at home, have drifted into the dead battery zone, or are just feeling lazy.

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