All Questions
17
questions
1
vote
1
answer
54
views
How to justify sound propagation is a linear time-invariant (LTI) system?
Background
A linear time-invariant (LTI) system (black box) is one described by the system:
\begin{align}
\dot{\xi}(t) & = A\xi(t) + B\omega(t), \; \xi(0) = 0 \label{eq-abc-1}\\
\lambda(t)...
- 151
0
votes
0
answers
27
views
Comparison between wave equation theory and transfer function theory
I deal with analysis of acoustic signals in solids. And after some literature research in physics and mathematic, I have a question about the followings two theories:
Wave equation theory: Imagine I ...
0
votes
0
answers
21
views
FWHM and Beam Width of transmitted beam of ultrasonic (ultrasound) transducer
Im a studying ultrasonic transducer and I got a question about FWHM and Beam Width while solving some problems.
In the lecture, I learned that Beam width is calculated by:
$2\Delta\theta = \frac{3.8\...
- 43
0
votes
0
answers
24
views
Is the strongest acoustic signal always the closest?
I have a single beam echosounder that I use to measure the distance to an object underwater. It emits an acoustic pulse and listens to the reflections. Using the time of flight and the strongest ...
- 1
22
votes
12
answers
8k
views
How do computers store sound waves just by sampling the amplitude of a wave and not the frequency?
All of this just doesn’t make sense though.
I mean, doesn’t the amplitude represent the loudness and the frequency the pitch? Aren’t they completely independent from each other?
Is the book just ...
- 390
0
votes
1
answer
58
views
Can multi-instrumental sound be reconstructed from a waveform?
This question came about when I saw someone wearing clothing with a waveform on it. I wondered if it would be possible to reconstruct the original sound from the printed waveform.
I understand that a ...
- 101
7
votes
2
answers
561
views
What do I hear when listening to a computer-generated sine wave?
When I use a sine-wave generator (such as this one), I give credit to the software and my hardware that a pure sine wave is produced (as close as is technologically possible) — that is, no harmonics. ...
- 173
1
vote
2
answers
85
views
Signal Processing – Discrete Fourier Transform and Incomplete Fourier Series
I'm working on a paper where I'm collecting sound pressure data from a chord's wave and trying to create a frequency spectrum to find the individual frequencies that make up the chord.
However, I can'...
- 13
1
vote
1
answer
96
views
Can we decompose sound like white light is decomposed (dispersed) in different colors?
When we send white light through a prism, the light is decomposed in the colors that constitute it due to the different velocities which different frequencies. Is there a way to decompose "white ...
0
votes
1
answer
103
views
How to solve this problem involving the "longest interval"?
The problem is shown as follows:
If one wants to make a digital record of sound such that no audible information is lost, what is the longest interval, $\Delta t$, between samples that could be ...
2
votes
3
answers
313
views
Can a sound wave begin with rarefaction?
Some digital recording samples (audio files) of recorded acoustic sounds present sound waves which begin with rarefaction. Is this an actual phenomena that can occur or is it a result of sound ...
- 23
3
votes
1
answer
70
views
Sound an amplifier makes when you plug / unplug a cable [closed]
When you plug, unplug or even touch a jack cable of an aplifying system with speakers, one can hear a low-pitch sound that is of roughly always the same frequency, which does not seem to depend on the ...
- 2,469
0
votes
1
answer
59
views
Subtracting Audio from a Song with Multiple Forms
This question may start oozing into the realm of copyright infringement, but let's discuss the theory first and foremost.
I have a song with vocal and orchestral accompaniment from a well-known movie ...
- 109
1
vote
3
answers
7k
views
Do electromagnetic waves produce sound?
Preamble:
At 5 AM in the morning, if I sit quietly and listen attentively, I can hear many different noises, on a very high frequency. If I try to isolate the ones that are less noisy, I can clearly ...
- 1,793
0
votes
1
answer
196
views
How can one change the virtual position of a sound source with a fixed array of speakers?
I have a question about signal processing:
How to make a person, sitting between array of two loudspeakers (one from the left and one from his right), hear the sound that came from both loudspeakers, ...
- 109