Project 3

Podcast Intro:

*music intro “Passion” by PinkPantheress*

Welcome to the Passion Podcast where we talk about all things music and language.

*music*

In today’s episode, we will take a whirlwind overview of the foundational aspects of sound design, music production, and acoustic linguistics.

*music outro*

Spectrogram Intro

What you’re looking at right now is called a spectrogram. It shows the strength of various frequencies over time for an audio signal. In this particular spectrogram, the lower frequencies are to the left and higher frequencies are to the right. Signals shown in white are played in the center channel or what we call “mono” audio, and those in blue represent the right channel, while those in orange represent the left channel.

Now what may be confusing is that when we say a voice has a specific pitch, we would expect sound to come from only one frequency and as such we would expect to see only one line in the spectrogram.

For example, if I were to play a C3 note on a piano, we would expect to only see one line in the spectrogram, like so. 

*play C3 sine wave*

As you may have gathered, that was not a piano sound, but a computer synthesized sound wave. The name of this wave is known as a sine wave. It is the simplest sound wave and it is unique because it is perfectly periodic and has a perfectly smooth curve in its sound wave.

Instead what we get from a piano is this.

*play C3 piano note*

So where do these other frequencies come from? The truth is the majority of sounds that occur in the real world (aka not computer generated) are actually very complex sound waves that include multiple frequencies occurring at once. In some instances, there are an infinite number of frequencies that occur in the same general area, resulting in a randomized sound wave. This is best exemplified by a fan sound, a clap, glass shattering or a snare drum. Alternatively, in other naturally occurring sounds that do contain pitch, like those from your voice, a piano, guitar, violin, or tuning fork, there are a series of overtones that accompany what we call pitch. Normally, we only care about the lowest note creating sound and refer to that as the pitch, but there is a series of overtones which are specific additional frequencies at predictable intervals inherent to some natural sound.

Music Theory

This brings us to a bit of music theory. Now usually this is a taxing subject but I promise there’s an interesting connection between what you’re seeing right now and how the music we listen to everyday connect. Going back to that series of overtones, there’s actually a link between what a voice produces and the way that a piano is set up. The first interval is kind of boring since its the same exact note only an octave higher. But the next interval is what’s known as a perfect fifth, or seven half steps up from the root note. What’s interesting is that when you play two notes on a piano where the second is a perfect fifth up from the first one, the overtones overlap exactly on top of each other at this perfect fifth note!

Here’s that C3 piano note again.

*play C3 piano note in left channel*

And here’s a G3 piano note.

*play G3 piano note in right channel*

So if I play a C3 and a G3 at the same time, they should overlap not at G3 but from the first perfect fifth of the C3 note in its harmonic series, which would be G4. So I’ll play both of these notes at the same time and pay attention to the G4 frequency. 

*play C3 in left channel and G3 note in right channel*

This perfect fifth interval gives a perfectly regal and anthemic sound to two notes played at this interval.

In a similar way, there is a major third interval within the harmonic series. For C3, this will be E3 and they will overlap at E5, so pay attention to that frequency.

*play C3 in left channel and E3 note in right channel*

This major third interval lends itself to a majorly bright and uplifting sound.

On the other hand, there are certain intervals that are not as pleasant sounding when played together. For example, there is a minor third interval which creates a more jarring overlap higher in the harmonic series.

*play C3 in left chanel and Eb3 note in right channel*

The minor third provides a sour and melancholy sound.

Sound Design and Music Production

When sound at its simplest is pitch, volume, and panning, how do producers create such lush and dynamic songs? Audio engineers are able to use many different effects to simulate different environments or create new unnatural sounds. Some more familiar effects might include

*reverb effect*

Reverb

*delay effect*

Or Delay

Another more sophisticated effect is bitcrusher. A bitcrusher effect on vocals gives a robotic and tinny sound. Pay attention to the high frequencies of the following song clip and how perfectly straight the lines are. This creates an unnatural sound for what is supposed to be a natural sounding voice.

*play “Follow the Leader” by Magdalena bay clip*

Bitcrusher is a form of distortion that affects what is known as the bitrate of the sound waves. You can think of bit rate as the audio equivalent of pixel resolution in images and videos. However, in audio, lowering the resolution of the bitrate not only creates a lower quality sound, it also adds sound to the audio through distortion. This is because it turns what originally will be a smooth sound wave into a more square wave resembling a staircase rather than a curvy mountain range. In doing this, higher frequencies are added based on the harmonic series. The effect is a robotic chiptune effect reminiscent of vintage video games. It is also said to give warmth to the sound if used softly.

The next two effects work in a similar way to each other. Flanger and phaser both play a sound (what we call a “dry” signal with no effect on it) and then layer it with the same sound on top (this is the “wet” signal because it has an effect on it which we will discuss). This creates a swirling and whooshing sound. Flanger creates a bunch of little striped bands of louder frequencies that shift up and down along the frequency spectrum. I’ll show you an example of a flanger in a song that works with panning instead of loudness, so the stripes you’ll see are differentiated by color and not by brightness.

*play “Stand Tall” by Childish Gambino clip*

Flanger works by delaying the wet signal and playing it right after the dry signal. This shift creates an almost rotational effect as the dry and wet signals gradually come in and out of time with each other. The result is a cascade of movement that can propel a song forward.

Phaser creates a single band that you will see in the spectrogram that moves up and down along the frequency spectrum. The reduced number of bands creates a softer effect when compared to the flanger.

*Play “Rapid Racer” Lone clip*

Phaser works differently by having the wet signal be altered by an all-pass filter. An all-pass filter works by changing the phase of certain frequencies. The phase of a wave is the polarity of the wave, so whether the actual waveform goes up then down or down and then up. This creates a similar swirling effect as the two sounds go in and out of phase with each other.

Acoustic Linguistics

Audio has an inseparable intersection with language. Our vocal tracts have a unique ability to produce a range of sounds in different combinations to make up words. 

Vowels are the most sonorous, or resonating sounds we can produce. They display the full range of the harmonic series.

*clip of [a] vowel*

By adding more constriction in our vocal tracts and suppressing the air that passes through, we can produce the next set of sounds which are glides. These are slightly less sonorous than vowels. Notice how the [w] sound is lacking certain frequencies in the middle of the spectrogram.

*clip of [w] glide*

Another less sonorous sound can be created by having a very close constriction in the vocal tract to produce a fricative sound. These include the [s] and [z] sounds. Notice how the following sound does not have the harmonic series and instead appears to be an infinite number of frequencies in a certain area played at the same time.

*clip of [s] fricative*

There is also a distinction in linguistics known as “voicing” which expresses the quality of a sound to require vibration of the vocal cords. You can place your hand on your throat and say [s] and then [z] and notice how your mouth stays in the same position but your vocal cords vibrating distinguishes the two sounds. 

This also has an effect on what we see in the spectrogram.

*clip of [z] fricative*

Because of how systematic language is, it is relatively easy to simulate a human voice using a computer and many Vocaloid programs have been developed for use in music.

Here’s a little sample of a Vocaloid to celebrate you learning so much about music and language today!

*clip of Miku Vocaloid*

Outro

*music outro “Passion” by PinkPantheress begins*

So next time you’re listening to your favorite song, I implore you to think about whether the song is introducing otherworldliness, movement, depth, or something completely different through its sound design. I hope you can consider what went into getting that unique sound that you love, and realizing that there is so much going on beneath the surface of the sounds you hear.

*music*

Thank you so much for joining me in today’s episode of the Passion Podcast. Take care!

*music outro*