As you all may know, the role that the mind plays in how we perceive audio is a very significant one. Audio engineers who are aware of psychoacoustic principles and other “mind tricks” can use them to great effect when making music or sound tracks. This basic concept can also be used to help you train your ear for audio production in a form of “reverse engineering”. I hope to list a few of these tricks here in the hope that they can help someone become better at hearing aspects of audio, either where they are present or where they are lacking. They might even help you to “hear” some of the processing techniques and their artifacts that might be eluding you at the present time.
As an example, one of the early frustrations I remember having as a musician, and then again as a hobbyist audio producer was my inability to “hear bass” in a typical musical reproduction scenario. For live performances I could “feel” the bass and if standing the right distance from the source, could often hear the lower mids of a bass guitar, but not in headphones or on a stereo system. It has taken me a long time – probably 15-20 years – to get to where my ears are now with it. For me the trick was to listen to musical examples which I was familiar with, then high pass filter them aggresively to “take all the bass out”. I started with the high pass up somewhere around 150 Hz and gradually pulled it down until I could no longer hear the difference it was making. Then I would A/B the bypassed and processed signal a few times to really listen for the change in overall tone. Over time I got to where I can now hear changes of 3db down to about 30 Hz on a good day. This process took awhile and yielded positive results. However, after performing this exercise for some time, I realized that for me, the secret to “hearing bass” is this: understand how bass affects overall tone, learn to recognize it when it is NOT THERE. After this, when I try to go “hunting for the bass” with my ears, I try to imagine what the track would sound like with no bass, and BAM it hits me in the ears.
Other quickie tips:
When trying to set relative levels for tracks within a mix, it is often helpful to listen to a track other than the one you are setting the level on, particularly one that “overlaps” in its contributions to the overall tone with the track you are trying to level. An example here would be to listen to the kick drum while you move the fader for the bass guitar. Once you feel that the track you are adjusting is starting to “step on” the other track, try to evaluate the respective levels at that point. If you back down on the bass guitar fader, do things sound better or worse?
When trying to set relative levels for tracks within a dry mix, it is often helpful to pan the two tracks to the same position or place your mix in Mono if it is not already in Mono. Then try to picture in your mind where your ears are telling you the instruments are. Is one “off to the side and slightly behind” the other? Is one instrument “in your face” while others are more distant? The goal here isn’t necessarily to get all of the instruments to sound like they are the “same distance” from the listener, but to develop a picture of where the performers might be if this were a live performance situation. Once you have a good picture in your mind of where things “sound like” they are, you can then adjust as seems fit to your idea of where they “should be”. The big trick here is to think of “quieter” as “further away”, and to consider this “distancing” concept when performing other tasks like panning the parts within the stereo field, or applying additional processing.
When listening for changes in dynamics in audio you are trying to analyze, try to close your eyes and perform the “distancing” visualization at a point of reference. Think of the changes in dynamics as either the listener “getting closer to” the elements of the mix being boosted (or the whole “virtual band”) or as these elements “moving away” from the listener. Often this really helps me notice somewhat subtle changes in volume. Instead of trying to think of one track getting quieter/louder than another the picture in my mind is of someone quickly “ducking behind” one or more of the others, or one performer “stepping forward” toward the listener. In this sense, the ear and mind are actually AMAZINGLY capable. In the real world, your ear can distinguish subtle re-orientations of audio elements in your surroundings, as well as more sever re-orientations.
Additional aspects of audio can lend a hand/hurt things when taking this distancing approach. Learning to listen to these aspects in everyday life can tremendously help hear when something is “off” with respect to the overall imaging of the “mental picture” of a given piece of audio, and also help you to understand when to/not to process the audio to enhance/soften imaging of individual tracks or the mix as a while. Examples of this are what the “initial sound” of a given musical contribution is (described as transients, punch, whack, attack, etc.) the sustaining portions of the contribution, and “how they fade away” or decay. Listening to each of these aspects on each “instrument” or “actor” in a mix/everyday world scenario can really open your ears to how timbre itself is formed and perceived. This will help you to understand when source material is “overcooked” or “too raw” or just right and in a lot of different directions. Focusing your listening to one element, whether in isolation.
When performing EQ moves as a form of audio correction, think of boosts as “more likely” to cause phase issues than cuts. This is even more true when you have several tracks competing for the same frequency domains in a mix. This technique can help you lean toward subtractive EQ first, which tends to sound more “natural” to the human ear. Even though it is true that EQ cuts can introduce phase relationship problems that did not exist prior to the cut, they are likely to be less audible and occur only at low volume and in the areas that are being demphasized, thus making them less perceptable, again particularly in the mix.