SOUNDS OF SCIENCE

PHYSICS IS PHUN – March 2007

SPlease be seated

SWelcome and Thanks (Dan)

SWeb Pages of Interest

STitle Page

Comment: Analysis of why sounds sound the way they do.

SReference Book

1. STANDING WAVES AND THE OVERTONESERIES

SThe Overtone Series

DOvertone series with Fourier synthesizer

TRANSVERSE WAVES

SStanding waves on a string

DG3-28: SUSPENDED SLINKY

SThe Overtone Series

DH4-31: VIOLIN

LONGITUDINAL WAVES

SStanding waves in air columns

DG3-28: SUSPENDED SLINKY

SThe Overtone Series

DH3-14: TWIRL-A-TUNE

Comment: In real instrument many harmonics combine to produce complex wave.

STANDARD ELECTRONIC WAVES

SStandard electronic wave forms

DH1-13: WAVEFORM GENERATOR, SPEAKER AND OSCILLOSCOPE.

(a)sine wave

(b)sawtooth

(c)pulse train

(d)triangular wave

(e)square wave

(page 2)

2. FOURIER SYNTHESIS

SFourier’s Theorem

Comment on Fourier’s theorem (amplitude and phase)

DH4-01: FOURIER SYNTHESIS

(a)sine wave

(b)sawtooth wave

(c)pulse train (optional?)

(d)triangular wave (optional)

(e)square wave

Comments:Harmonics create wave shape and sound

Change amplitude (hear) and phase (do not hear)

Generalize to any wave

4SSlides of synthesis of triangular wave, sawtooth wave, pulse train, square wave

3. FOURIER OR SPECTRUM ANALYSIS

SFourier analysis or Spectrum analysis

ELECTRONIC WAVES

DH4-02: FOURIER ANALYSIS - WAVE SHAPE AND SPECTRUM

(a)sine wave

(b)sawtooth

(c)pulse train

(d)triangular wave

(e)square wave

4SFourier Spectra

(a)sine wave

(b)sawtooth

(c)pulse train

(d)triangular wave

(e)square wave

(page 3)

MUSICAL SOUNDS

SAnalysis of Musical Sounds

2SRecorder background

DH4-02: FOURIER ANALYSIS - WAVE SHAPE AND SPECTRUM

(a)recorder

(b)violin

(c)crumhorn

(d)clarinet

4SFourier Spectra

(a)recorder

(b)violin

(c)crumhorn

(d)clarinet

SFactors in Tone Quality

DH1-52: AUDIOTAPE 82 MIN - SCIENCE OF SOUND - LONG VERSION (Overtones)

Comments: transients (piano, tuned percussion)

inharmonicities (tuned percussion, piano)

vibrato

chorus effect

4. FORMANTS

SSinging Formant

SOrigin of vocal formants

SSimplified formant model

SVocal formant examples

DH4-02: FOURIER ANALYSIS - WAVE SHAPE AND SPECTRUM

Vocal Sounds

(a)ooo

(b)ahh

(c)eee

SFormant Regions for Vowel Sounds

DH4-02: FOURIER ANALYSIS - WAVE SHAPE AND SPECTRUM

Vocal Sounds

(a)vowel sequence: boot-all-balm-but-bat-met-bit-beet

(b)eee at various frequencies

(page 4)

5. AUDIO SPECTROGRAPHS

Comment: Time dependence of audio spectrum

DAUDIO SPECTROGRAMS

SVOCAL FORMANTS FOR VOWEL SOUNDS

DH4-02: FOURIER ANALYSIS - WAVE SHAPE AND SPECTRUM

Vocal "WOW"

DH6-06: SYNTHESIZER - WOW

SSynthesizer and voice "WOW"

SVoice spectrograms of four words

Comment on use of formants to teach speech to profoundly deaf persons

DH6-04: HELIUM VOICE

SDangers of breathing helium

SHe and SF6 Voice

DH6-05: SULFUR HEXAFLUORIDE VOICE

SThanks to Colleague for helping with program.

SGoodbye

Pre-Show Demonstrations

H4-02: FOURIER ANALYSIS - WAVE SHAPE AND SPECTRUM (Oscilloscope)

H5-01: EAR MODEL

RESONANCE TUBE WITH PLUNGER

H4-11: SAVART'S DISKS

H4-53: MOOG ROGUE SYNTHESIZER

H4-55: YAMAHA DX7S DIGITAL SYNTHESIZER

G3-28: SUSPENDED SLINKY

H3-05 KUNDT'S TUBE - OSCILLATOR DRIVEN

H3-13 ROARING TUBE - 8 FT

H3-17 FLAME TUBE

WAVETEK ON AUDIO CART (Guess the frequency.)

SOUND LEVEL METER (Guess the decibel level.)

CLICK ILLUSION CART (in hallway)