Questions tagged [acoustics]
Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. Applications of acoustics are for instance the audio and noise control industries.
129 questions
1 vote
1 answer
45 views
Plotting the spectrum of a 94dBSPL signal from a Calibrator
A standard calibrator produces a 1KHz sine tone at 94dBSPL, An RTA I used captured the max peak as 97 dBSPL, but the spectrum was plotted with the max value as 94 dBSPL. What's confusing me is 94 ...
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1 vote
1 answer
81 views
Common practices for acoustic dB SPL measurements, from pressure vs. time signal
I have not had formal training in acoustics and common practices in acoustic measurements. Let’s say I have a microphone that gives me a Pa vs. time digitized signal. I want to report the SPL in dB. ...
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1 vote
1 answer
113 views
How to apply sensitivity curve to acoustic data
I have an underwater sound signal obtained from a hydrophone in "Counts", of the order of ~10^7. Here is a slice of it : The manufacturer gave me a frequency response correction function ...
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3 votes
2 answers
159 views
Creating A FIR Filter From An IR or Room Calibration Data
I'm trying to create FIR filter coefficients from a IR or data from a room calibration capture. I'm hoping to create a filter that compensates for the acoustics of a room. I'm hoping to put these ...
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0 votes
1 answer
82 views
Calculating the signal shift of acoustic emissions between a source and an observer
I am attaching two sensors on a body that I would like to investigate for defects. I am creating an impulse response on the first sensor by hitting the bolt that it is fastened by with a sharp object ...
- 103
0 votes
1 answer
72 views
USE Impulse response to get Original sound
I am a student majoring in acoustics. My English is not very good, so I apologize in advance. In my project, I am dealing with impulse response in room. Find the impulse response function between the ...
- 3
3 votes
2 answers
392 views
physical energy definition for acoustic signals
Recently I am reading Books "Signals and Systems" from Oppenheim and "Ultrasonic testing of materials" from Krautkrämer. In those books there are some definitions about wave energy:...
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1 vote
2 answers
51 views
What is the difference of calculating signal power that using these two methods: using moving average filter and using forgetting factor?
The conventional signal power calculation can be: $$ P(n) = \frac{1}{N}\sum_{i=0}^{N-1}x^2(n-i) $$ $x(n)$ is the signal. However, I have seen another method: $$ P(n) = \lambda P(n-1) + (1-\lambda) x^2(...
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3 votes
0 answers
82 views
Improving the Time Domain Normalization of Acoustic Sound Data
I have tried to evaluate the analog microphone (IMP23ABSU) built into the STEVAL-STWINKT1B with the FP-SNS-DATALOG1 (HS-Datalogger). The values were exported as "raw values" (this is an ...
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3 votes
1 answer
84 views
What effect causes this Pattern?
I've conducted a measurement of underwater noise in a laboratory experiment. Therefore i am using a sweep signal. Sometimes -I guess when the signal is much more louder- I get this fascinating ...
- 31
1 vote
2 answers
105 views
Modeling an Acoustic Reflection from a Wall - a Paradox?
I am trying to simulate the reflection of a sound ray, that goes from a sound source, bounces off a wall, and is received by a microphone. The wall has a an absorption coefficient, and a specular ...
- 153
2 votes
1 answer
125 views
What does the frequency of oscillating microphone feedback depend on?
Pointing a microphone to a connected loudspeaker creates a feedback path and usually results in acoustic resonance, which manifests in a sustained oscillation: https://youtu.be/_XTtjZ8aZbc. A similar ...
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1 vote
1 answer
105 views
How to extract pressure values from a WAVE file?
Possible a duplicate but I could not find a direct answer. I used a sound card (Focusrite, at 96 kHz sampling frequency) connected to a calibrated hydrophone to record an ultrasonic signal, with a ...
- 11
1 vote
1 answer
65 views
Modeling end-blown flute instrument using adaptive filter
I want to find the resonant frequency of specific end-blown flute called Persian ney, Using LMS in arrangement of system identification. Two signal is needed for algorithm: system excitation (...
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0 votes
2 answers
142 views
How can sound waves be modeled in a manner that distinguishes individual voices but also recognizes words?
More specifically, I'm curious how we can represent sound waves in a way that would both distinguish between individual voices and also recognize, e.g. that recordings of different people saying the ...
