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0answers
23 views

Difference between note based (MIDI) and sampled (FLAC, MP3, etc.) audio formats

I (somewhat) understand sampling and sampled formats, and their relation to the original (analog) signal, but do not quite relate it to note based (MIDI) formats. What actually is a note based audio ...
1
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1answer
35 views

Is there an audio processing library/API that contains all standard features of a digital audio workstation?

I need an audio processing library/API (in any programming language, preferably Java or Python) that is able to do things to sound waves such as: sum/mix sources together, apply EQ, dynamic EQ where ...
1
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0answers
22 views

Using K-Space Filtering to Filter by Speed

I want to read waves with an electret consender microphone that are slower than the speed of sound, and I figure it would make those waves easier to identify if I could process out all waves moving ...
0
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1answer
33 views

Why standard Waveform from audio out gets distorted when i reduce the amplitude?

In my attempt to generate a standard sine wave out of a sound card, i started using matlab which has a function soundsc for scaling the output ...
0
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0answers
26 views

Sound of sin(x * sin(x)) without accumulation

Tried this at the Mathematics board, but as someone there pointed out, perhaps this is better suited for the DSP board. I'll repeat the question as I asked it there: Playing around with the sine ...
1
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1answer
70 views

Baby Cry Sound detection

I wanted to write a code to detect baby cry sound. I am using Windows as platform. Presently, I am able to get audio samples and its frequency plot(using FFT) but not sure how to proceed forward. I ...
0
votes
1answer
29 views

Cancelling the acoustic echo that occurs with a variable delay and volume

I am trying to build a software that records audio to a server and then broadcasts that audio into the same room that the microphone is present. This means that the audio signal is uploaded to the ...
0
votes
0answers
32 views

Why sonar not used as radar?

When we want to do ranging and detection in air the first idea comes to mind is of RADAR. Sonar is mostly related to underwater stuff since it has less attenuation as compared to EM waves used in ...
0
votes
1answer
51 views

Detecting a specific pop in a real time audio signal

I am listening for a very definite pop in a real time audio signal. So far I have managed to get the audio signal in at a sampling rate of 44100.0 Hz and 2048 frames per second. I have visualized the ...
3
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1answer
124 views

Does our brain constantly ifft to hear?

From my understanding our ears have hairs/cilia in the cochlea that resonate at frequencies within our hearing range. To me this means we are hearing in the frequency domain as opposed to the time ...
0
votes
1answer
58 views

How to emulate human sound recognition

A person can recognise a large variety of sounds and fairly subtle differences in sound, even if they have only heard the sound once. Is it possible to recreate this with software, and how? ...
0
votes
1answer
73 views

Normalizing the magnitude of Goertzel Filter c#

I'm trying to detect some frequencies of 18Khz with sample rate of 44100 [samples/sec]. When I pass a buffer(~4500 samples) to the algorithm it returns a magnitude in a very strange range. Sometimes ...
0
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1answer
39 views

Ways to identify if music has vocal timbres in it?

The human voice is singular because it has a specific frequency spectrum and fast transitions between vowels and consonants. What are good and computationally fast ways to detect if there is probably ...
1
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1answer
67 views

Controlling one signal with another one (Rocket engine effect - Subtractive synthesis of sound)

I programming some sound effects in Java and exporting them into .wav files. Currently, I am trying to program a rocket engine sound effect. I want to do it in the following way: The sound of a ...
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1answer
66 views

Effect of frequency shift on a sound signal

I had two sound files and did the following to it: ...
3
votes
4answers
146 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 ...
1
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0answers
35 views

amplitude compensation after filtering and mixing audio

I am working on a mixer which lets me mix dry and wet signal in a user defined ratio. Wet signal is basically just the all pass filtered signal. The mixing takes place in frequency domain and so does ...
0
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0answers
14 views

A Suitable DSO Replacement

Currently I have a Pipeline leakage detection system the concept is that we are using a striker to strike the pipe at the generator side and receive the sound waves at the receiver side both separated ...
0
votes
1answer
37 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 ...
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0answers
55 views

How to process the .wav file to get meaningful information like the number of inhales/exhales

The plot of the data from the wav file. Link to the sound file - https://drive.google.com/open?id=0BxAPlY66uX7qWWtDZUw3WkpjSGs&authuser=0 Also the FFT plot is like this I am new to the field ...
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votes
1answer
90 views

Feature extraction for sound recognition and classification

I am building an application that would "listen" to the microphone input, analyse it, and compare the analysis to a pre-analysed and pre-classified sound bank (small - maximum 20 sounds). It will then ...
0
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0answers
50 views

Running 2D array through FFT in matlab

I have an input file that is a 2D array but don't know how to convert code that I have to accept the original file and bandpass filter around 18-20 for frequency and then create the bandpassed output ...
0
votes
0answers
114 views

Removing background noise (sound) by attenuation below certain amplitude (loudness) in MATLAB

I have to write a MATLAB code that attenuates sound at low amplitudes to zero, in VoIP. Meaning I have to reduce low amplitude sound to zero E.G. while speaking I have some background noise (like the ...
1
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1answer
54 views

Calculating the power of a signal

I'm trying to calculate the power of a signal and my tutor has given me this formula to do it I've spent the past while building a program and now the foundations are there it's time to implement ...
0
votes
2answers
39 views

Acoustic record and store devices

I am working on a project involving analysis of bird sounds and I want to record these sounds in slightly remote locations. It is enough if the device can only record and store them (maybe in an SD ...
0
votes
1answer
265 views

How to convert Third Octave data into single SPL quantity

I have a data vector which consists of calibrated pressure at each sampled point in time. I have also taken this signal, applied a filter bank to it using a butterworth filter with passbands according ...
1
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1answer
70 views

Filtering noise and identifying phones boundary in speech recongition

I am planning to do a self project on speech recognition for a vocabulary detection system using arduino. I know CMUsphinx or bitvoicer is probably the way to go. But I would like to code the project ...
0
votes
2answers
183 views

Tutorial for a stereo Phaser in C++?

I was searching for a tutorial on how to implement a stereo Phaser in C++. All i´ve found was sourcecode with little or no explanations which did´nt help me much. Does anyone know a Tutorial with ...
1
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1answer
160 views

Find similarity of sound signal

So I was working on a program to comparing the similarity between the pronunciation of a word, First I got the audio file, and I use FFT on it to get the amplitude over frequency array, then I just ...
0
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6answers
175 views

Call recognition using Digital Signal Processing

We are looking for writing applications which would recognize Bird calls and Frog calls using Sound processing. EDIT: I want to identify the species of bird / frog and do not want to differentiate ...
2
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2answers
36 views

What are the parameters of transducer that I can get from an Anechoic chamber?

I have a bunch of piezo elements, that I want to use as "Mics", for that I will test their reaction in a Anechoic chamber. My question is what the are characteristics that I can measure that describe ...
1
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0answers
162 views

How to add bandpass filter to recorded sound in matlab

I have a sound that is being recorded but I am trying to apply bandpass filtering to the sound so that it filters out anything above and below a selected frequency range. I have tried the tool in ...
0
votes
1answer
21 views

How to choose a microphone and make sure not to overcharge (clip) it?

I'm not sure that's the right forum to ask this question but I'll do it anyway. In my project, I've to listen to different machines using a MEMS mic by fixing the microphone directly on to the ...
0
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0answers
54 views

Detecting white noise signal and narrowing the frequency in matlab

I created a white noise that is played in 2 channels. While the left channel is active the right is silent and vice versa. I am trying to detect the signal arrival time after it has run through the ...
0
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1answer
50 views

Segmenting a sound file before each of its attacks

Like the title says... I want to split audio file where a single instrument is played (not so fast)... I just need to detect the attack phase of the waveform to know where a played note begins. Can ...
1
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0answers
168 views

GCC-PHAT cross correlation

I am trying to implement GCC-PHAT in python. The approach is similar to the following two links: link1 and link2 It seems the only difference between GCC-PHAT and normal cross-correlation using FFT ...
2
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1answer
75 views

Air-coupled microphone

Does anyone know what the heck is a coupled-air microphone? I know that they were used for recording internal body sounds in papers like this and this. I googled the term, but I couldn't find any ...
1
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1answer
83 views

matching the mouth shape of an audio file(lip sync)

I am working on something like cartoon, but the character's mouth shape is automatically detected and matched by the word they are saying. my guess is to use speech recognize algorithm to analyze ...
0
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1answer
35 views

Inter aural time difference generation using sine waves

I have a stereo sound for Inter aural time difference consisting of sine wave(16 samples as 16 bit PCM Data) for left and right audio. From time to time I would like to advance either the left or ...
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5answers
422 views

Pitch Detection: avoiding frequency doubling / halving

I am working on a tuning app. I have so far tried 3 different libraries with a number of different algorithms. However, when I compare to other tuner apps, I seem to be getting frequency doubling on ...
1
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2answers
111 views

Recognizing bodily noises (ie, not spoken words)

I was pointed here by a chain of stackoverflow posts. I'm a software developer looking to make a module that recognizes noises like snorts and coughs. Here was my original question on stackoverflow ...
1
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0answers
56 views

How to synchronise two audio files using a marker

I'm working on a project on which we use WebRTC and the RecordRTC library to record audio files. I would like to be able to process the audio files server-side to ensure a good synchronisation. To ...
1
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1answer
52 views

How can I connect multiple microphones to my computer (more than 4) and process the outputs independently? [closed]

I am trying to create something like a heat map for sounds originating in a classroom to study the discussions inside the classroom. For this I am instaling directional microphones in various parts of ...
1
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1answer
1k views

Feature extraction for sound classification

I'm trying to extract features from a sound file and classify the sound as belonging to a particular category (eg : dog bark, vehicle engine e.t.c). I'd like some clarity on the following things : 1) ...
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5answers
2k views

What are the audio equivalents of images like “Lena”, “Mandrill”, and “Cameraman”?

I don't know what to call these images, but they're very often used in the image processing world as standard examples to show the output of a particular operation. Here's a link to the page ...
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1answer
158 views

how to read full input signal with STFT in matlab

Please help! I am trying to figure out why in the code i have below my input signal is being cropped but in the code I have a full signal created. The white noise created is 5000 samples for the right ...
1
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1answer
62 views

What does it mean for audio to be 'sped up'? How can I undo it?

I very simply have a .wav audio file, but there is a note with it that says "This audio has been sped up by 10x". I am wondering, what does it mean exactly from a signal processing perspective for an ...
0
votes
1answer
2k views

how to apply Short-time fourier transform to code in matlab

Please Help, I have a white noise signal that I created and need help to apply the Short-time fourier transform to my code so that it can do the bandpass filtering. I am trying to put it in the code ...
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2answers
277 views

Android: fundamental frequency

I want to find the fundamental frequency for human voice in an Android Application. I want to use autocorrelation method. My code is this: ...
0
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1answer
117 views

How to Concatenate white noise signal and applying bandpass filter matlab

I created a white noise signal. I am trying to use the array I have created with the white noise to play in 2 channels. When the left channel I was trying to have 5000 samples and the right will have ...