Smartphone measurement capability:
Speakers
produce sound, left and right channels
Pulses, tones, harmonics, volume control
Audio output may be sent to external amplifier and speakers
Microphone
record sound
analyze for time delay of pulses (speed of sound?)
frequency analysis
loudness (dB meter)
Acoustic quality
Experiments
Young's double slit experiment done with sound waves
set up two speakers, send pure tone to both, in phase
listen for interference modes in the far field
measure constructive and destructive interference using the microphone.
How does audio fringe pattern change as tone is changed?
What happens with more complex tones?
Speed of sound
Measure speed of sound by producing a sound pulse and measuring time required to detect echo
point speaker at a wall a known distance away
speed equals 2 times the distance (there and back) divided by time of flight
What effects the speed of sound? Humidity? Tone frequency? gas media?
Does sound travel in a vacuum?
Musical Instruments
What tones are produced by common musical instruments?
Are the tones pure, or do they have natural harmonics?
How much of the quality of tone comes from the instrument, and how much from musician?
Assemble five trumpet players, with five different trumpets
Record each trumpet player playing a set of notes
Have each player repeat, but with each trumpet
Speakers
produce sound, left and right channels
Pulses, tones, harmonics, volume control
Audio output may be sent to external amplifier and speakers
Microphone
record sound
analyze for time delay of pulses (speed of sound?)
frequency analysis
loudness (dB meter)
Acoustic quality
Experiments
Young's double slit experiment done with sound waves
set up two speakers, send pure tone to both, in phase
listen for interference modes in the far field
measure constructive and destructive interference using the microphone.
How does audio fringe pattern change as tone is changed?
What happens with more complex tones?
Speed of sound
Measure speed of sound by producing a sound pulse and measuring time required to detect echo
point speaker at a wall a known distance away
speed equals 2 times the distance (there and back) divided by time of flight
What effects the speed of sound? Humidity? Tone frequency? gas media?
Does sound travel in a vacuum?
Musical Instruments
What tones are produced by common musical instruments?
Are the tones pure, or do they have natural harmonics?
How much of the quality of tone comes from the instrument, and how much from musician?
Assemble five trumpet players, with five different trumpets
Record each trumpet player playing a set of notes
Have each player repeat, but with each trumpet