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Questions tagged [wave]

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Need help with detecting onset of audio in wav file

I'm new to DSP and I'm learning as I go. I have an audio file with a chirp signal(2kHz). I played and recorded this chirp signal and the recording has a lot of environmental sounds. Here is my code:
PhoenixProject's user avatar
3 votes
2 answers
320 views

Why do waveforms that are symmetrical above and below their horizontal centerlines contain no even-numbered harmonics?

All About Circuits site states that waveforms that are symmetrical above and below their horizontal centerlines contain no even-numbered harmonics. Can somebody explain this mathematically, or point ...
robert's user avatar
  • 133
-1 votes
1 answer
60 views

are Ultra sound signal amplitude dangerous? [closed]

First sorry if this question if it's out of topic but I'm very intrigued The human ear can hear a specific range of sound waves frequency. and huge amplitude of those sounds can damage the ears but ...
Lkaf Temravet's user avatar
-3 votes
2 answers
143 views

difficulty in understanding amplitude, frequency and period

I have difficulty in understanding of some fundamental terms as amplitude. Can be there more than one amplitude for a signal? The following expression is combination of 3 sinusoidal signal, so are ...
Soner from The Ottoman Empire's user avatar
0 votes
1 answer
277 views

Is it possible to encrypt an audio wave? NFL Example

In the NFL, quarterbacks receive playcalls from coaches over their helmet's wireless interface. Someone mentioned how occasionally, these radios will pick up interference from airplanes, and that ...
steve antwan's user avatar
0 votes
1 answer
152 views

frequencies in sound: multiple possibilities?

First, I am by no mean a sound engineer (as you will guess later). I was just wondering something while looking at the waveform of a .wav for a given shape of waveform on a duration of 2 sec for ...
Kroma's user avatar
  • 103
0 votes
1 answer
5k views

Extracting metadata from wav files [closed]

I was curious if there is a way to extract metadata from wav files. For instance, can you get bpm, key, instrument, etc. from a .wav file on upload?
Cody Rutscher's user avatar
4 votes
2 answers
280 views

How to Extract a Period of a Periodic Pulsed Signal?

I rercorded a sequence of zeros and ones which is repeated many times. However, the first and the last repetitions may not be complete because I have to start recording at a random time, so the ...
Natalia Molinero Mingorance's user avatar
0 votes
1 answer
387 views

Windows Audio WAVEFORMAT buffer BYTE to 16-bit int

I am trying to understand audio-buffer processing at the low-level for the first time. I have the following C++ code copying WAVE-format byte data from capture buffer of Window Core Audio (*ppData in ...
blisstdev's user avatar
  • 103
-1 votes
1 answer
318 views

How to compare two audio files that maybe have been recorded in the same environment

I have two audio files that I think they were recorded in the same room. Is there any tool that can be used to compare both of them. Knowing that sample rate and format are the same. Thanks
Safi's user avatar
  • 1
0 votes
0 answers
396 views

Equation for impulse train

I am looking for a formula (Fourier series) to generate an impulse train waveform - a spike-wave with amplitude and period both $1$ – so that $f(x)$ has value $1$ at $x = 1,2,3,4...$ and $f(x)$ has ...
Richard Burke-Ward's user avatar
4 votes
2 answers
15k views

Mathematical equation for the sound wave that a piano makes

Is there a mathematical function that can output the sound that a piano makes at different frequencies? So if the simplest equation for a sound wave (at a given frequency and for a given sample rate) ...
Murey Tasroc's user avatar
0 votes
2 answers
95 views

Pitch fluctuates unexpectedly in simple sine function

I wrote a very basic C program to play a sine of a user-specified frequency. In the interest of portability, I have it spit values directly to stdout, so hopefully you can reproduce my problem on your ...
Ian Martin's user avatar
1 vote
1 answer
172 views

When simulating a voltage divider using wave digital filters I get inversed polarity outputs

I'm studying wave digital filters for my bachelor's thesis and I'm finding problems in implementing a voltage divider to test my knowledge. Here's the circuit that I'm trying to simulate and the WDF ...
Matheus Oliveira da Silva's user avatar
1 vote
1 answer
353 views

wavwrite with 32 bits per sample seems to overflow?

I am trying to generate a 32bit PCM wav file with octave, the file shall contain a single full-scale sample (0db impulse). I am getting the expected result when using 24 bits per sample: ...
sergej's user avatar
  • 173
1 vote
1 answer
79 views

Is there a special case in which wave atoms convert to curvelets?

I'm new to multi scale transformations. I was wondering if there is a special case where wave atom converts to curvelet transform? Can I use wave atom parameters to have curvelet properties?
MJay's user avatar
  • 467
5 votes
1 answer
515 views

How to triangulate 2 sources on a 2d plane formed by 4 sensors?

I have 4 sensors capturing signal data. Signal distribution speed is constant and known. I have sensors positions in 3d space. Also, I have an amplitude/frequency decomposition for data received by ...
Blender's user avatar
  • 51
2 votes
1 answer
4k views

How to "draw" the function/wave to send symbols using QAM?

Say you have the following 8QAM constellation diagram: Say, you want to send the sequence: 001 110 101 000 001 How would you draw the function/wave containing the symbols? My problem in ...
SwiftedMind's user avatar
0 votes
1 answer
47 views

In DSP - is it true that the only type of interfering wave occurs when frequencies match? [closed]

Therefore, any other frequency, no matter the amplitude, won't interfere or degrade original wave in the DSP frequency domain systems?
Rain's user avatar
  • 113
0 votes
1 answer
744 views

Pulse wave from sum of sinusoids

...
bzrr's user avatar
  • 103
0 votes
1 answer
2k views

Combining 2 sinusoids of equal amplitude with different frequencies into 1 new "wave"

This question is about combining 2 sinusoids with frequencies $\omega_1$ and $\omega_2$ into 1 "wave shape", where the frequency linearly changes from $\omega_1$ to $\omega_2$, and where the wave ...
MisterH's user avatar
  • 317
0 votes
1 answer
798 views

How do I sum the discrete cosine transform cosine waves?

Sorry if this sounds like a stupid question, I'm new to DCT. I've implemented various types of DCT (like IV and II) and they all give vastly different coefficients. From what I've read, the DCT ...
user4757174's user avatar
2 votes
1 answer
826 views

How audio watermarks are captured

I have read that we can use audio watermarks to "identify the original produces of the material or the consumers of the media." How consumers of the media is measured by audio watermarks? Lets say ...
sravis's user avatar
  • 121
2 votes
1 answer
437 views

Why LFO should be alias-free?

I'm really tripping about this point! I try to reason with you and explain what's my trouble. Consider a scenario with Sample Rate 44100hz and a LFO square wave that will modulate some internal ...
markzzz's user avatar
  • 45
2 votes
1 answer
2k views

Generate loopable sine wave cycle for given frequencies

I am somewhat new to DSP so bare with me. I am working on a simple wavetable oscillator. What I am trying to do is generate one cycle of a wave form for each note (frequency) and store it in an array ...
djex's user avatar
  • 51
1 vote
2 answers
295 views

How to mix two audio files recorded with different settings to obtain a realistic result

I am a software engineer, currently working on a signal-processing related project, which I am new to. For evaluating the algorithm(which is written in R), I need to mix (merge) two different audio ...
sämi's user avatar
  • 11
1 vote
2 answers
3k views

Moving Average of sinusoid

If you calculate a simple moving average over a window length that is equal to the period of the sinusoid, you get a straight line (=0 because the wave is symmetric around the X-axis): the wave has a ...
MisterH's user avatar
  • 317
1 vote
2 answers
336 views

If you had supersonic hearing, would you be able to hear the carrier wave of an AM radio station?

Would you be able to hear the carrier wave of an amplitude modulated station, if you could hear in the MHz range, or would the high frequency be filtered out after rectification?
Kunal Chopra's user avatar
7 votes
2 answers
15k views

Can you turn a square wave into a sine wave using a low pass filter?

And if it could, would it make the sound of the square wave thinner than before because of losing its harmonics?
Mark 's user avatar
  • 71
4 votes
2 answers
924 views

Signals cross-correlation

I am trying to measure phase difference between two received waves which are recorded by two separate PC's (microphones). The two PC's starts recording at the same time, then I make a sine wave sound ...
Redan Hassoun's user avatar
0 votes
1 answer
153 views

Computing of speech signals modulation entropy

I got a question regarding to modulation entropy of audio signal. There is some literature I found about this topic, http://www.irit.fr/recherches/SAMOVA/FeaturesExtraction.html#me. I've read sample ...
user3038744's user avatar
0 votes
1 answer
144 views

Adding sine waves

I need to play thousands of simple sounds (generated tones) at the same time. If I am understand correctly there should be a way to add them together in complex wave but i really can't see the light ...
Alexey Demidov's user avatar
2 votes
1 answer
1k views

How do you construct common waveforms (square, sawtooth, triangle, noise) from sine wave partials using an IFFT?

In the lovely image below we see the addition of sine waves making a square wave. I am coding a wave table synthesiser and thought it would be great to get the user to be able to fiddle with the ...
Aran Mulholland's user avatar
1 vote
0 answers
1k views

Python: write .wav to chosen directory [closed]

I can only write .wav files to the current directory fname = 'bassswoon.wav' wav = wave.open(fname,'w') wav.writeframes(struct.pack('h', bassswoon)) wav.close() ...
yunque's user avatar
  • 103
1 vote
1 answer
5k views

How to perform sine generation (in C)?

I am interested in how should a listing for a program look like that will generate a sine of f=50hz, using the next arguments for any moment in time. ...
mypaul's user avatar
  • 13
2 votes
1 answer
20k views

Generating a noisy sine wave in Python, efficiently

(Questions after code block.) For now, I am generating the sinusoid and the noise separately and then normalising the amplitude so I can write the signal to a .wav file (16-bit, 16kHz). ...
yunque's user avatar
  • 103
3 votes
4 answers
637 views

Why every musical instrument sounds different than any other while listening?

This is soft question.I am not expert in music. We know that English language has 26 letters (which are again grouped into vowels and consonants) , while language of music is same all over the world ...
devraj's user avatar
  • 407
0 votes
0 answers
119 views

Formatting issue WAV - MP3?

I have two "sources" of audio: record WAV audio files (44.1kHz, 16bit, stereo) with Linux arecord and convert them with LameMP3Encoder to MP3 files (44.1kHz, 320kbps, 32bit**, CBR)*** record MP3 ...
msc's user avatar
  • 23
0 votes
1 answer
192 views

What is the Sound of a Solution to the Wave Equation?

What is the sound of a solution $y(x,t)$ to the Wave Equation $\frac{\partial^2y}{\partial t^2}=c^2\,\frac{\partial^2y}{\partial x^2}\enspace$? To be clear, I don't look for a solution of the Wave ...
Vertex's user avatar
  • 122
4 votes
3 answers
4k views

Removing unwanted square-wave noise from a signal

I have a signal, s, given at the end of this message. I need to remove the square wave shape from it. The desired signal is actually very small and it has been contaminated by a strong square-shape ...
Alberto Castillo Graza's user avatar
1 vote
2 answers
2k views

FFT calculation suitable, Wav File, Java

If I have a wav file with this characteristics: 16bits (2 Bytes per Sample) 32000 Sampling Rate 60 Seconds 2 Channels then I have: ...
Anita's user avatar
  • 171
1 vote
1 answer
182 views

Unsupervised learning algorithms to detect anomaly in waves

I have a sample of graphs (more than 10000...). that look like in the image below: I am searching for an unsupervised learning algorithms that can help me to detect anomalous observations. Here what ...
dmitriy's user avatar
  • 111
1 vote
1 answer
4k views

Downsampling PCM Audio

I'm looking everywhere for solutions for audio downsampling. However for one reason or another they are incomplete, sometimes buggy, and sometimes are in a programming language I cannot understand. ...
Enrique's user avatar
  • 11
0 votes
1 answer
1k views

Convert Triangle Wave to Sine Wave

I have this triangle wave as input: and I want to derive a sine wave out of it. How do I go about it? PS: I am doing this in Lua, so any piece of code close to that language would be appreciated.
arj's user avatar
  • 13
0 votes
1 answer
603 views

Given two waves, 441 Hz and 700 Hz, how many samples long is each wave's period if the sample-rate is 48 kHz?

The title says it all. I have two waves, Master and Slave. Master is at 441 Hz and Slave at 700 Hz. The sample-rate is 48 kHz. I want to know how to calculate the period of each wave in terms of ...
Dave Chambers's user avatar
1 vote
0 answers
220 views

generating a waveform in matlab for rohde and schwarz signal generator

We are doing a test which consists in sending a waveform from Matlab to the signal generator SMB100A and sending it through a cable to the r&s spectrum analyzer just to have a channel. We set the ...
Natalia Molinero Mingorance's user avatar
1 vote
1 answer
2k views

Does Wav format supports writing complex values

I have a sine tone, doing some math, and finally gets an harmonically accumulated sine tone in complex numbers. I do want to preserve the phase information of imaginary part on the other end, which ...
nmxprime's user avatar
  • 207
1 vote
3 answers
3k views

Wav file scale factor

I seek a scaled audio file format for my dsp output. I'd like to produce "scaled wav files", when I've done my pre processing. Eg. if the amplitude is 15.5 (of whatever unit), you should be able to ...
Illishar's user avatar
  • 133
0 votes
1 answer
687 views

Instantaneous phase calculation problems

I am currently struggling with a problem when calculating the instantaneous phase of a wavefield using a 1D Hilbert transformation. The scheme is as follows. 1D Hilbert transformation of wave field $...
MichaelScott's user avatar
0 votes
1 answer
58 views

Spectral Content of two waveforms

I have found this interesting question here: Which of these two waveforms has a richer spectral content, and why? Intuitively speaking, I think that the first one is richer, but I cant really ...
ExceptionCaught's user avatar