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2answers
57 views

Measuring how “non-noisy” a sound signal is

Given a sound clip (whose source is an FM radio signal) I'd like to measure how different from background noise (the "in-between channels" noise) the sound clip is, so that I can compare the ...
3
votes
1answer
60 views

How to compute dBFS?

I asked myself how to compute dBFS (dB full scale) from a value of sample between 1 and -1? and in general?
1
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2answers
31 views

Generating Music Tones, How to handle when tones overlap? (16bit samples) [duplicate]

If i add the two tones then the result if two peaks are added together will be greater then the the sample max (2^15). For the life of me I couldn't think of the right words to google. Think i have ...
2
votes
1answer
74 views

How to make pop-free, crisp two-beep ringtone?

I hope this ultra-noob question is not entirely out of place here. I'm trying to make a super simple ringtone: 0.5s silence + 1s "pure tone" + 0.5s silence + 1s "pure tone" + 0.5s silence. By "pure ...
1
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1answer
73 views

What is the DTW result (applied to the MFCCs of an audio file) proportional to?

I have computed the MFCCs for two audio files and applied the DTW to both sets of coeficients for both files. Now each such pair the two files is described by one single value (computed by the DTW). ...
1
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0answers
20 views

Length of frames for calculating cepstral coefficients

For audio classification we are using the cepstral coefficients and their derivatives. Which I calculate using the Matlab libary voicebox. I am looking for some literature for how to choose the frame ...
0
votes
0answers
29 views

Differentiate between two sounds made by same person

I want to know if i pronounce alphabet "A" then i pronounce alphabet "B" how can i detect the difference between these two sounds. I know a sound is characterized by its frequency and amplitude but ...
1
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0answers
26 views

How to convert a sound file to any other data format which can be manipulated

I know this is very basic question and i am new to this site. But can anybody help me with my question. How to convert a sound file to other data format say using some type of transform (FFT or DFT) ...
1
vote
1answer
77 views

How to decide the number of cepstral coefficients?

For audio classification we are using cepstral coefficients, but how should I decide the number of coefficients?
3
votes
1answer
57 views

Ultrasonic data transfer

I am trying to send a short amount of data (10-15 characters) from one mobile device to another via (inaudible) sound within 1-2 seconds. I'd like to be able to deal with normal external noises ...
0
votes
0answers
63 views

Getting sound pressure level (SPL) for a frequency band from Welch's derived PSD

I'm using Welch's method (pwelch, in octave) to get the PSD of a recorded sound signal (i.e. pressure level vs. time). I then took the PSD data and took the sum of the amplitude in each octave band ...
5
votes
1answer
225 views

PC-to-PC data communication over Sound FSK / PSK / DSSS

For fun and work I've to implement a java based application that can Encode text or data to sound and transmit using PC's speaker and on the receiving side is a microphone with decoder software. I ...
0
votes
1answer
40 views

Calculating the gain for adjusting sound level to X db

I have a sound signal, and I would like to implement a simple realtime level control (for info, I am using Pure Data, but I'd like to know about the general case). For this I thought of using the ...
0
votes
1answer
112 views

Generate buzzer sound

I'm trying to generate a buzzer sound like this one in matlab. When you look at the waveform, it's got sinusoidal notches cut into an otherwise normal looking sinewave. I generate a sinewave tone, ...
1
vote
1answer
108 views

Sinusoidal Synthesis of audio

I am working on a sinusoidal encoder & decoder to compress .wav files. For now I am trying to regenerate the audio by combining all the frequencies of the original .wav file. Here is the code I ...
5
votes
2answers
249 views

How is a human whistle a pure sine wave?

According to Wikipedia human whistling is a pure sine wave. If that is true and if a human is whistling and produces a rhythm like any song, is he still producing a pure sine wave? For example, if I ...
0
votes
1answer
95 views

How to perform sound synthesis?

I am generating a simple musical instrument using a ST board. basically I have a sensor which detects motion or spatial angle and generates sounds of differnt pitch and volume depending on the angle. ...
1
vote
1answer
139 views

Recorded an audio file using microphone via Windows Sound recorder, but has 2 channels that are slightly different. Why are they different?

I recorded sounds using a plug in microphone on a Windows 7 laptop. I used the Windows Sound recorder to record the sounds. It was only one microphone, but when I load the sound file into Audacity, it ...
-1
votes
1answer
69 views

How to amplify sound wave

I'm developing a singing game and I want to output player's voice through speakers. I'm using portaudio for that, I acquire the input signal and just write it to the output buffer. The problem is the ...
1
vote
1answer
133 views

What features describe audio signals? (Besides frequency and amplitude)

I recorded sounds with a microphone and I try to distinguish them in my Java program. The frequency works quite good, but if I look at the fourier transforms it seems like there should be more ...
5
votes
3answers
258 views

How to de-noise raw sound data

What techniques/algorithms can I use to remove noise from a raw recording of sound (voice)? The purpose is to get a smoother graph (removing the "jaggedness"). What I have tried was to average-out ...
2
votes
2answers
184 views

Loudness of PCM stream

I'm receiving PCM samples through stream which is one channel, 8000 samples per second. I figured out way of finding out loudness by calculating 'force' of signal by adding abs value of every next ...
6
votes
5answers
368 views

Why Do I Get This Crackling Noise on Zeroing out the High Frequencies?

I recently started playing with the Fourier transform (after spending a few weeks learning about the mathematics behind it). I decided to try hacking together a low-pass filter on the following sound ...
-1
votes
4answers
258 views

Can FFT be used to find peaks and pits on audio files

I'm able to read wav files and its values. I need to find peaks and pits positions and their values. First time, I tried to smooth it by $\frac{(i-1 + i + i + 1)}{3} $ formula, then searching on ...
1
vote
0answers
117 views

Tool for Harmonic Analysis & Synthesis

I've been using a program for identifying harmonics for a wave after doing a fourier analysis. http://www.phon.ucl.ac.uk/resource/sfs/esynth.htm I would like to be able to tweak some of the ...
10
votes
2answers
220 views

Sound synthesis effects for natural sounds

I´m currently working on an accordion synthesizer and I would like to make it sound as natural as possible. I really like how the following wave sounds: ...
3
votes
2answers
301 views

Is there any free software that can recognize and classify sounds?

i am making a smart home automation software and i would like to know if there is any software that can recognize noises such as speech ,playing music,phone ringing etc The exact software i am looking ...
2
votes
1answer
353 views

Maximum frequency of any mobile phone speaker

Which is the maximum frequency of a speaker of any common mobile phone? I would like to use sound to repel some animals, so I need playback sampling rate to be above 44100 Hz.