All Questions
Tagged with signal-processing acoustics
59
questions
36
votes
7
answers
12k
views
Why can't you hear music well over a telephone line?
Why can't you hear music well well over a telephone line?
I was asked this question in an interview for a university study placement and I unfortunately had no idea.
I was given the hint that the ...
- 499
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
19
votes
6
answers
3k
views
Can we quantify the pitch of a sound that is a mixture of many frequencies?
How is the pitch of a sound defined quantitatively when it is a mixture of many frequencies? For example, the sound emitted by a plucked guitar string, or say, the pitch of somebody's (normal) voice. ...
- 11.8k
12
votes
8
answers
5k
views
Feynman claimed "The ear is not very sensitive to the relative phases of the harmonics." Is that true?
In The Feynman Lectures on Physics, Dr. Richard Feynman claimed that the ear (I assume he meant the human ear) is not sensitive to the relative phases of harmonics.
However, I was asked to test ...
- 145
12
votes
3
answers
4k
views
Avoiding radar detection using active noise control instead of a stealth fuselage
was reading about different stealth technologies used by modern aircrafts to avoid radar detection.
Wouldn't it be easier to have a receiver on the airplane listening on the radar frequencies and then ...
- 131
10
votes
6
answers
3k
views
Can sound waves be modulated?
Can you modulate sound waves? Like can you have a sound wave of a relatively low frequency and modulate it with a sound wave of a much higher frequency which people cannot hear and send it through the ...
- 101
10
votes
2
answers
1k
views
Why does a wall act as a low-pass filter?
Learning about the fourier transform and its connection to filtering/convolution got me curious about naturally occurring filters.
Why/how is it that brick walls naturally act as a low-pass filter (...
- 101
9
votes
4
answers
3k
views
Sound of a limited wave after removing main frequency?
From my old studies in signals I can remember that "a signal limited in frequency domain is unlimited in time domain" and viceversa (a signal limited in time domain is unlimited in frequency domain).
...
- 737
9
votes
2
answers
4k
views
How to distinguish female and male voices via Fourier analysis?
What makes one, without looking, be able to identify the gender of the talker as male or female?
I mean if we Fourier analysed the voice of males and females, how the 2 spectrums are different which ...
- 17.1k
8
votes
1
answer
3k
views
Ringing sound when you flip a coin?
When you flip a coin, you hear a ringing sound. I know that the source of the sound is the thumbnail hitting the coin, but it seems to be filtered by the spinning of the coin. Specifically, the faster ...
- 905
7
votes
5
answers
2k
views
How exactly does a seashell make the humming sound?
My little brother asked me where the ocean-like sounds came from inside of a sea shell. I told him that the air trapped inside the shell vibrates, making a sound. But then he asked me why the air had ...
- 12.5k
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
6
votes
1
answer
1k
views
Frequency shift without affecting signal length
Non-physicist here.
From what I've learned in university and what common sense says, a shift in frequency of a signal results in a change in its length in time. For example, if a sinusoid signal of ...
- 171
4
votes
1
answer
667
views
Significance of higher harmonics
I am analyzing a noise signal and have identified the fundamental frequency of a tone and it's higher harmonics. Say for example given the signal below,
The fundamental frequency has a sound pressure ...
- 41
4
votes
1
answer
1k
views
How to determine frequency components present in distorted signal, with the set of possible components already known?
I am trying to choose the best approach to digitally analyse a signal, which is a mix of an unknown number (but less than 16) fundamental signals at specific frequencies (e.g., sines).
The goal is ...
- 141