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0
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0answers
22 views

modify main sound with second sound (matlab)

So i have 2 sounds. Main sound and second sound which represents "parking garage" effect. So i want to modify main sound that sounds like it's playing in parking garage. ...
0
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0answers
27 views

Sound recognition within an audio signal

I'm trying to do some tests in Android. The phone's microphone is continuously listening, and whenever a balloon is blown, I would like to detect it. There are of course other ambient sounds/noises. ...
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1answer
33 views

make a voice sound signal play faster

Suppose $x(t)$ is a signal containing a voice. How can one derive a signal playing the same voice faster. I tried $x(t+\lfloor{100t\rfloor}/100)$ to double the speed; But it adds a buzz sound. Is ...
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0answers
16 views

Equation for Resultant of Multiple Whitenoise Signals

Please pardon my ignorance. The image above shows a plot of intensity of whitenoise sound signal recorded on a microphone from two speakers (A and B). Speaker A constantly emits white noise, while ...
0
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1answer
23 views

sound pressure level(SPL) from .wav of a heart sound [duplicate]

I am trying to get SPL from .wav of a heart sound but I dont know what kind of data I would need. in the other questions, some said calibration factor but I couldn't find it in the manual of the ...
0
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1answer
20 views

How does a sound card translate amplitude values to sound when playing WAV/PCM/FLAC files?

I'm reading the documentation for WAV files (and importing them in C++)It seems like 44100 amplitude (this can change, and is specified by the WAV header) values get sent to the sound card every ...
0
votes
1answer
153 views

How to measure acoustic pressure level under water with a hydrophone?

this is my first post here and I am also new in signal processing. Let's say I have a hydrophone with amplifier which is connected to a sound card plugged in to a computer. I gather the sounds to a ...
0
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0answers
12 views

Computing rotor blade segment angles and distances

I'm stuck at the moment and I suggest that I've made some flaws in developing a code. I'm trying to implement a function what computes the following angles and the distances (distance = observer to ...
0
votes
2answers
73 views

How to convert a sound signal function to wave file? [closed]

I am new to understanding sound signals. A sound signal, as far as I know, is a real function of time $x:[0,\infty)\to \Bbb R$. For example, $x(t)=\sin(t)$ is a sinusoidal signal. What is $x(t)$. For ...
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0answers
17 views

Seismology - PPV / VDV from geophone waveform data

I'm using an inexpensive seismometer to try and measure the effects of local HGV traffic on buildings. The device is connected to a Raspberry PI that has a Cirrus Logic Audio Card. The signal is fed ...
3
votes
1answer
98 views

Proof-of-concept for active noise cancellation to block consistent low-frequency HVAC noise transmission

Background We live in a multi-unit building where each unit's HVAC system/closet is located directly across a party-wall from the neighboring unit's bedroom, and adjacent to a shared external curtain ...
1
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2answers
83 views

Is spectral centroid enough to measure brightness?

i'm new in this group and i'm studying a sound signal. I have used FFT for extrapolate frequencies and see the harmonics of this sound. I have to compare this sound with another similar sound and find ...
0
votes
1answer
34 views

Detecting whether reverb is present

I have two different audio short samples of an instrument playing. If one of the samples has a reverb effect applied, how easy is it to detect which sample has reverb? Is this possible?
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3answers
85 views

No-lag causal bandpass filter kernel formula

Can anyone point me towards a formula for a good (for any values of "good") no-lag causal bandpass filter? I am doing sound processing and I need to identify starting points of certain sounds (target ...
0
votes
1answer
75 views

Measuring Amplitude of sound wave FFT

Please, pardon my ignorance. This may be a simple question, but I am still unable to explain what is happening. I am using a turtlebot to listen to sound emitted from a stationary sound source. My ...
0
votes
1answer
75 views

Uncertainty Relation between time and frequency

Typically, humans can hear sound waves in the frequency range 20 Hz to 20 kHz. If one wants to make digital record of sound such that no audible information is lost, what is the longest time interval ...
3
votes
2answers
116 views

Pitch perception - Why does our ear not directly detect the missing fundamental frequency?

My motivation for this question is related to biological phenomenon of our inner ear, so I initially posted in the biology community, but I suspect the answer has a DSP explanation, so I figured this ...
0
votes
0answers
13 views

Signal processing methods for identification of multimedia descriptors for feature extraction (semantics)

It is said in https://www.amazon.co.uk/Multimedia-Semantics-Metadata-Analysis-Interaction-ebook/dp/B005E8AG66 that While there has been a lot of work in the signal processing research community ...
0
votes
1answer
21 views

Repair audio file [closed]

I have an audio recording, recorded using my smartphone. The audio format is .aac and is around 90 minutes long. The first 65 minutes of the audio file plays excellently, but then the audio is kinda ...
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votes
2answers
372 views

How can I calculate Reverberation Time (RT60) from the Room Impulse Response using Python?

I have the following Room Impulse Response(RIR) in wave format here. I wanted to calculate Reverberation Time (RT60) of it by plotting its Energy Decay Curve using this Python code. The RIR is ...
0
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0answers
42 views

Sound and Vibration Signals- Frequency content

I am not sure if here is the right place to ask such question. I am missing my physics classes right now and maybe you guys can help me. Or give me some tips for researching the theme (biblio) I am ...
0
votes
1answer
46 views

is there a way to apply a median filter diagonally?

For example, some studies show how to smooth a spectrogram with a 2D median filter vertically and horizontally (along time or frequency). My question is how would I apply 2D median filter along the ...
0
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0answers
14 views

is there a way to separate transients by length?

Suppose we have a mixture audio signal, consisting of very short transients and some that are a bit longer (in ms, or s) along with other material, like harmonics, etc. But focusing only on transients,...
0
votes
1answer
204 views

How does it go about implementing pitch shifting without affecting the duration or speed on matlab? [closed]

I am creating a project that will record a sound sample from the world, for example, a bird's chirping. And then through pitch scaling, I could create different notes. I first tried to change the ...
4
votes
1answer
126 views

Algorithm for identifying beat grid in music with non-constant tempo

Are there any algorithms for automatically fitting a beat grid to a song (tempo matching) when the song has a slowly changing tempo or BPM? The output would be a vector of onsets. Here's a picture ...
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0answers
24 views

When we play several audio streams what is responsible for mixing them?

When we play several audio streams what is responsible for mixing them in single audio playing via speakers? Clearly it should be either OS combining the sounds or hardware getting multiple data ...
0
votes
1answer
26 views

How to model airborne sound channel

I'm making a soft demodulation/decoding to communicate a microphone and a speaker in short range. I have to calculate the LLR using my constellation and the airborne sound channel probability density ...
0
votes
1answer
644 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) ...
0
votes
0answers
22 views

Intensity to voltage

I am using a formula for Interaural Intensity Difference. link So if one ear should hear 0.8 of the intensity of other ear. How would that translate into reduced voltage for the headphone speaker? ...
3
votes
1answer
56 views

How exactly does sound get encoded by a cochlear implant processor?

I've been wanting to know more about how sound is processed by a cochlear implant processor, how they are programmed, and how they stimulate the magnets and electrodes inside. How do you take pure ...
2
votes
0answers
196 views

PortAudio: sound fade in/out by scaling sample data

I've done already some fade in or fade out effect in portaudio, but that is not working properly. My callback function: ...
0
votes
2answers
94 views

recognize unwanted sounds, noises, and deleting them algorithm

I have a function that I need to use denoise algorithm on. What I thought is to divide it to smaller parts and then use Fourier Transform on each one of the parts, but I am not sure what to do next. ...
4
votes
1answer
295 views

Polyphase Filter decomposition. It is not working

So, I want to do a polyphase implementation of a filter bank (I had problems with it since the beginning and I already asked for help to the community in the past, indeed: Norm MPEG-1 Layer III (Mp3) ...
11
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3answers
1k views

Transmit data through sound between 2 computers (very close distance)

I'm writing an example on transmitting data through sound betwwen 2 computers. Some requirements: The distance is very close , i.e the 2 computers are basically adjacent to each other Very little ...
1
vote
2answers
53 views

Custom ringtone sounds good on computer, can't be heard on phone [closed]

I did a ringtone using Audacity and then used this website to convert to mp3. I sent this mp3 file to a friend who said he couldn't hear it well. I have an iPhone so I converted it to m4r. Both the ...
0
votes
2answers
76 views

How to label sound events in noisy .wav files

I'm trying to find a way of automatically identifying birdsong in phone-recorded sound files (1min long). Currently the algorithm I'm using doesn't label all of the events I want it to. (it is ...
0
votes
1answer
884 views

How to transform SoundWave Picture to sound?

I would like to recreate a sound from a picture of a soundwave. But i see a lot of theorical question. And im not sure its possible.... I mean, it is possible to create a sound... But to make ...
0
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0answers
31 views

Sync on minimum/falling edge

I have a signal that I want to process (with Java) and so far I'm making good progress. However, the devil is in the details. For reference, it's a sound file at 48000Hz, 16-bit, I'll refer to samples ...
0
votes
1answer
155 views

Normalizing audio waveforms code implementation (Peak, RMS)

I have some audio data (array of floats) which I use to plot a simple waveform. When plotted, the waveform doesn't max out at the edges. No problem - the data just needs to be normalized. I iterate ...
0
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0answers
54 views

Realtime detection of a simple sound

I was wondering if there are any simple tools I could use to detect a particular sound in realtime (and of course ultimately take some action after that). This is a loop of the sound I want to ...
0
votes
1answer
541 views

Delay-and-sum beamforming: implementing steering in C

I am currently trying to understand how delay-and-sum beamforming works. I have found this website which explains the process of this technique very well in which the following C code is provided: <...
1
vote
1answer
34 views

Why does this video's audio change depending on the playing device?

Yesterday I noticed that if I played this video from my smartphone on speaker, one could barely hear anything. On the other hand, if I used earphones I could hear it perfectly. Then, I tried with ...
1
vote
1answer
116 views

Harmonic Product Spectrum algorithm. I dont understand one step

I was looking some Harmonic Product Spectrum algorithm examples and I came up with this: ...
3
votes
2answers
459 views

Generating inaudible sound waves using MATLAB

I want to generate inaudible sound waves (above 18kHz) with 48kHz sampling rate using MATLAB. Generating a sound wave with 18kHz frequency makes it inaudible. I've inserted the data in the 18kHz ...
0
votes
0answers
67 views

Compensating for drifting phase picked up from a wave using Goertzel's Algorithm (DFT)

I'm sending some data through sound at a specific frequency. Currently, I'm using ASK-modulation and goertzel's algorithm as a bandpass filter for demodulation, but I'm looking into doing this with ...
2
votes
0answers
490 views

What does Fast and Slow Time Weighting signify for real-time audio signal processing?

I have a streaming audio signal that I am recording in real time. To make the explanation easy, say the signal that I receive is calibrated and has a sampling frequency, $F_s = 44100\textrm{ Hz}$. I ...
1
vote
0answers
58 views

How to convert multi-band Energy Time Curve (ETC) to Impulse Response (IR)?

I am running my own sound simulator. Now I have obtained the Energy Time Curve (ETC, expressed by energy) by physical simulation, and they are stored in 8 discrete frequency bands (because decay of ...
1
vote
1answer
675 views

How to find SPL of a WAV file given a calibration tone in WAV format

My ultimate aim is to find the Sound Pressure level of a digital WAV audio file and represent this (say, in MATLAB) as a dB SPL re 20 uPa on y-axis and frequency on x-axis. As this link mentions: ...
1
vote
2answers
533 views

Generating sound of particular frequency matlab

I want to generate a high frequency (single) tone. I am using matlab (any other platform/tool for the same will also work). I am using the following snippet which I wrote by referring to various ...
0
votes
2answers
170 views

Weird note structure on guitar audio waveform

Why do some times notes take these weird structures (circled below). That is a guitar monophonic audio waveform by the way (3 note melody). There are 3 notes played in this audio file. These are the ...