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3
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1answer
31 views

Proof from wave equation of upper limit of active noise cancellation

Anybody know of a proof of the hard upper frequency limit of active noise cancellation using the ear canal volume as a boundary condition to solve for the upper frequency limit? I keep on encountering ...
0
votes
0answers
27 views

Reverberation time reliability evaluation (ISO 3382-2)

I am processing reverberation times using the reverse-integration method described in ISO 3382-2 and I am a bit puzzled by the conditions sfor checking the result reliability indicator. One of them ...
1
vote
1answer
73 views

Normalize Fourier Transform For Video Game

I am in the process of developing a video game where I would like to sync a character's mouth with an audio clip of their speech that is playing. I found this great website that shows the profiles of ...
0
votes
0answers
49 views

MATLAB band-stop filter design for room reverberation?

I took acoustic measurements of a room using sine swept method, and I also used Pioneer sc-37 to obtain more accurate data. I used RoomEQ wizard software and measured the impulse response of the ...
0
votes
2answers
85 views

How to take acoustic measurements of a clasroom

I'm an electrical engineering major and I have a question regarding a project I'm working on. I'm supposed to design 3 band-stop filters on MATLAB for echo cancellation/suppression. My problem is ...
1
vote
1answer
156 views

What is the best method for measuring of room reverberation time?

I want to measure a reverberation time in the room. What is a best way to do that? What kind of signal should be used? I know about balloon and pink noise, but are there any better methods?
1
vote
2answers
65 views

separate static echos from acoustic signal (ICA?)

Iam using acoustic waves to measure the thickness of material. My problem is that the acoustical lense produces static echos in the signal. I try to seperate both because there is a short interference ...
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
2answers
156 views

Convolving Room Impulse Response with a Wav File (python)

I have written the following code which is supposed to put echo over an available sound file. Unfortunately the output is a very noisy result which I don't exactly understand. Can anybody help me with ...
2
votes
1answer
130 views

How is LMS/FXLMS noise cancelling different than simple polarity inversion?

Consider a noise-cancelling headphone: If I have a noise signal from the outside world, mic it, flip the polarity by multiplying by -1 (with an op-amp or digitally), delay by the appropriate amount, ...
0
votes
2answers
2k views

Confusion regarding reverberation time (RT60) calculation

I have some confusions regarding reverberation time (RT60). I need to calculate reverberation time from a given power envelope. This is what I get. As you might see the line is curved close to zero ...
3
votes
1answer
97 views

Underwater Acoustic Positioning

I have to develop an underwater positioning system which has to determine the position of a ROV. Four buoys will be placed on each corner of a swimming pool. Each one of these buoys will be equipped ...
0
votes
1answer
39 views

what is standard acoustic volume

In Audio Experts book, it's given as Sound pressure meters must be calibrated at factory to a standard acoustic volume. So what doth this ...
1
vote
0answers
19 views

Diference between Specific,perceived and perceptual Loudness

i came across many terms describing loudness ! I understood perceived loudness which is what the user perceived and is related to the user. What is specific loudness and perceptual loudness? ...
3
votes
2answers
69 views

Dealing with echoes / dead-spots in digital transmissions

I'm looking at communicating digital data through the air as soundwaves. To illustrate the problem, I generate a 10-cycle 2kHz wave, play it out through my MacBook's speakers and pick it up on my ...
2
votes
2answers
78 views

is there a second order approximation to perceived loudness

Quoted from this As a first order approximation it takes ten times the energy to double the perceived loudness So is there a 2nd order approximation. If so then how much change in RMS value ...
1
vote
0answers
37 views

Echo detection for localization

I was reading about active sonar and couldnt quite understand how the echos are recognized. My doubt is, when the sound signal is reflected back, it is greatly attenuated and distorted due to many ...
3
votes
1answer
679 views

Acoustic feedback detection algorithm

I am woking on an sound processing application where I have limited processing resources. I need to be able to detect acoustic feedback and then signal that such an event occurred. I am not concerned ...
3
votes
1answer
117 views

Estimating harmonic loudness

I'm working with data that looks something like this: ...
6
votes
1answer
241 views

How do Phons relate to loudness?

Let's say I have the very same signal stored in 2 .wav files. And lets say I process each file using a function, and it is established that one file is 20 phons ...
5
votes
0answers
532 views

What are reasonable levels for the ERLE (Echo Return Loss Enhancement) in acoustic echo cancellation?

I am working on acoustic echo cancellation which has a double talk detector. During the single talk, the ERLE (Echo Return Loss Enhancement) exceeds 100dB and during double talk around 20dB to 40 dB. ...