Noisy apartment neighbors
And how to live with them
In the last apartment I lived in, I had a few neighbors who like to play music. The music they liked to play had repetitive bass parts. When music passes through walls, the only part that makes it is the bass part. Thus, the part I heard was repetetive and annoying. (I don’t think they were even playing it that loud—the apartments just had thin walls.)
Of course, I talked to them about it, but it didn’t really fix the problem. So I just had to live with it. Until, one day, I figured out how to cover up that annoying sound, using white noise. Now, when neighbors play annoying music, I don’t have to listen to it for a second. The noise I play is not loud, not at all distracting, and while it’s worse than silence, compared to the annoyance of a neighbor’s bass beat, it’s a huge relief. Instructions below.
Skip the longwinded but hopefully interesting explanation.
All sound consists of a combination of vibrations at different frequencies*. Most melodic and pleasing sound consists of only a few different, related frequencies** combined together, whereas most “noise”, consists of a much larger number of frequencies with no particular relation to each other. White noise is a type of sound where all different frequencies are equally loud. This is the type of noise you hear on a TV channel with no signal, along with the “snow” in the picture.
*There are other ways of analyzing sound, but this is by far the most common and most useful.
**There’s a basic frequency, and additional frequencies that are multiples of that base frequency, called harmonics. For instance, a tone with a base frequency of 440 Hz (440 vibrations a second), would have harmonics at 880 Hz, 1320 Hz, 1760 Hz, and so on. Higher harmonics tend to be softer.
The human ear works by separating the incoming sound into the different constituent frequencies and then recognizing sounds based on the timing and volume of those frequencies. Now, an interesting effect here is called the “masking effect”. When a sound has two frequencies that are close together, where one is much louder than the other, the softer frequency will not be audible. As the frequencies get further apart, the difference in volume required for the louder sound to mask the softer increases.* The masking effect is what music compression algorithms use. They store frequency information for the music, but discard masked frequencies.
*Two frequencies that are *very* close to each other and of similar volume will produce what’s called a “beat” effect, which is similar to the sound of a helicopter’s blades when turning, except much softer. Beats tend to be hard to hear, though. Piano tuners who tune by ear use beats to do their tuning.
It’s possible to play pure white noise to mask out annoying sounds. But when you do this, it requires that every frequency in the white noise be louder than the loudest frequency in the annoying noise. Otherwise, it’s not loud enough to mask the annoying noise. But then, most of your frequencies are not going to be masking anything, and just make the masking noise much louder than it needs to be.
But when you have an annoying noise that consists entirely of low, bass sounds, you can mask it much more effectively by generating noise that doesn’t include frequencies higher than those you’re trying to cover up. Here’s how to do this:
Instructions
1) Download and install Audacity.
2) In the Generate menu, select “White noise”. 60-120 seconds is enough.
3) In the Effects menu, select “Low pass filter”. Type 100 into the the box. Press Apply.
4) In the Effects menu, select Repeat, or press Ctrl+R.
5) Repeat step 4 several times.
6) In the Effects menu, select Amplify. The default settings are fine. Press Apply.
7) Press Shift+Space, or click on the play button with the Shift key held down. This will play the noise in a loop.
8) Optionally, save this file as a .wav file, so you can quickly open it and play it later.
If at all possible, route your sound through speakers with powerful bass. This will make it more effective at lower volumes. Also, you can use earplugs to reduce the volume of the noise, to where it’s not so grating.
Step 3 applies a low pass filter that reduces the volume of all frequencies above the cutoff point by a certain amount. (I’m guessing it’s about 6 decibels.) Because you don’t really want any frequencies above that point, it’s necessary to apply it several times so that the reduction is complete.
You may notice that when the sound repeats, you hear a little click. This is because the sound level for most of the file (you can see this by zooming in a lot) changes very slowly. But the very end and the very beginning sound levels don’t match, so there’s a very quick jump there, and that leads to the click. You can actually get rid of this by deleting a bit from the beginning and end until the two levels match exactly. (It also helps when the slope of the line at the beginning and end match.) This would be much easier if Audacity had a looping tool, but I managed get rid of the click on mine.
If you can’t get rid of it, you can make the click happen less often by generating more noise in step 2.
