click below
click below
Normal Size Small Size show me how
Harmonics and Envelo
pe
Question | Answer |
---|---|
Harmonics and envelope give sound... | character |
Sine waves | most basic sound, simplest type of wave you can have. have flute-like character. No harmonics. (flute has a sound that contains very few additional frequencies) |
sounds are made up of multiple... | ...sine waves superimposed on others. |
complex sounds have... | ...a pitch made up of a fundamental frequency and additional overtone frequencies |
harmonics | what overtones are called in pitched sounds like musical notes. multiples of the fundamental. |
fundamental frequency can also be labeled as... | the first harmonic |
second harmonic | 2X the fundamental |
third harmonic | 3X the fundamental |
sawtooth wave | if all harmonics are present at the same relative amplitude. sounds like garbage. |
square wave | it all odd numbered harmonics are present at the same relative amplitude. Skip every other harmonic frequency (1, 3, 5, 7, 9, 11....) still sounds kinda bad |
Why can't you make a square wave with all even harmonics? | the fundamental is an odd number |
complex waves | ex. square waves and sawtooth waves. basis of analog subtractive synthesis (Moog, ARP, Buchla, etc.) (subtractive synthesis is filtering parts of the sound you don't want to hear) |
harmonics vs. overtones | harmonics can be called overtones, but not all overtones are harmonics |
How do we differentiate 'voices'? | harmonic content. Human voices and musical instruments all have different harmonics in different amounts. If you filter out harmonics, different instruments sound the same. |
What determines the harmonics content of your voice? | the combination of all the elements of your vocal tract; vocal cords, sinuses, oral cavity, etc. |
spectrogram | graph that indicates from left (low) to right (high) the frequencies that you're hearing |
Different vowel sounds have... | ...different harmonic content. Those high frequencies are important in allowing us to differentiate between the sounds in voices. |
Sibilant sounds have... | high frequency sounds that are important to keep so we can differentiate them |
What happens if you filter out too much high frequency? | You're left with unintelligible, muffled voices |
timbre | musical term for harmonic character of different instruments |
What are the two categories of sound? | pitched sound and noise based sounds |
pitched sounds | strong fundamental and harmonic frequencies. include voices and instruments and things that make melodies. |
noise based sounds | indistinct fundamental frequencies and overtones. drums and cymbals and any other non pitched rhythm instruments. Have frequencies that aren't multiples of the fundamental, so they're called overtones, not harmonics |
What determines our perception and recognition of a sound? | which harmonics and overtones are present, and at what level relative to the fundamental |
envelope | term used to describe the change that takes place to sound over time. How a sound stars, (suddenly or gradually) decays, and ends |
What does envelope apply to? | frequency, amplitude, and timbre (all change over time) |
audio tracks on digital editing softwares are a... | ...representation of the envelope |
What are the four basic elements that make up envelope? | attack, decay, sustain, release |
attack | energy enters the piano string, amplitude grows |
decay | point where sound (amplitude) is dying away the most rapidly, a little arbitrary and hard to decide for absolute sure |
sustain | amplitude changes very minimally |
release | sound ends. wave gets a little louder because you lifted the pedal up (for a piano note) |
dynamic range | difference between quietest and loudest sound accurately produced by a system. speech, music, movies, sound systems, etc. all have it. |
If multiple systems are present (i.e. cassette tape, amplifier, loudspeaker)... | ...each part of the chain has a measurable dynamic range, and the overall system also has a measurable dynamic range |
noise floor | level at which a system cannot produce sound without noise overcoming the signal. all signals carry some noise. e- in devices generate some level of noise that represents flow of e- through the circuits. represents lowest amplitude a device can produce |
generally the most expensive a device... | ...the lower the noise floor |
clipping | happens when a device is outputting its highest possible level of amplitude. nice and curvy sine wave has flattened peaks. becomes, essentially, square wave. makes sound seem harsh. over time can damage loud speakers |
clipped flattened tops represent... | ...a lot of VERY high amplitude, high frequency harmonics |
goal in system design is... | ...to keep signal above the noise floor and below clipping from source to output |