Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [audio]

Audio, or in terms of signal processing, an audio signal is an analog or digital representation of sound, typically as an electrical voltage.

Audio signals may be synthesized directly, or may originate at a transducer such as a microphone, musical instrument pickup, phonograph cartridge, or tape head. Loudspeakers or headphones convert an electrical audio signal into sound. Digital representations of audio signals exist in a variety of formats.

Source: Wikipedia.

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Hilbert transform to compute signal envelope?

I've heard that the Hilbert transform can be used to calculate the envelope of a signal. How does this work? And how is this "Hilbert envelope" different from the envelope one gets by simply rectifying a signal? I'm interested specifically in…
dB'
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How to create a sine wave generator that can smoothly transition between frequencies

I am able to write a basic sine wave generator for audio, but I want it to be able to smoothly transition from one frequency to another. If I just stop generating one frequency and immediately switch to another there will be a discontinuity in the…
Mark Heath
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What methods can be used to identify and remove echo from an audio system?

Background I am designing a system that will have a single small microphone and speakers for use in a phone type setting. Easiest example I can give is a Skype conversation where you are using your computers speakers and a desktop microphone. I am…
Kellenjb
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Learning roadmap for the audio signal processing beginner

I would like to start learning audio signal processing. There are numerous books online and academic papers all of which seem to skip the fundamentals of the topic. I would like to know a rough roadmap, so to speak, to follow in order to…
some_id
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Subtracting sensors output that have mutual inductnace between them

Background: The software that i use to anaylze my signals is matlab. I have two audio signals that were recorded using two magnetic sensors. Lets call one sensor A and the other one B. A and B have mutual inductance between them. While sensors A…
user1017064
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Audio output quality

When a digital device (PC, portable media player, etc.) plays a digital audio file (ogg, mp3, flac, etc.) the audio signal output is always the same, regardless of the device type/brand, am I right? Thus the sound quality should not differ. For…
sterz
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Pattern recognition for temporal data

I'm trying to detect and classify non-speech sounds. Currently, I'm using a series of moving overlapped power spectrums from training sounds as the features I am looking for. When I do analysis, I'm just computing the same amount of overlapped…
cufmo
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Can you represent an audio signal in any other domains besides time and frequency?

Maybe a stupid question, but if there is a time-domain representation of audio signal, and also frequency-domain, so is there any other domain that signal can be represented in?
apocalypse
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Prerequisites for audio signal processing

I started a DSP course online and quickly discovered that as much as some people say that it is possible to avoid the more advanced mathematics of signal processing, this didn't seem the case. It seems like a solid understanding of Calculus and…
some_id
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RMS values above 0 dbFS?

I wonder why several RMS meters I'm using for music production show RMS values above 0. For example, when using an input signal with a constant DC of 1 (0 dbFS), I get these results, although Wikipedia says that in such cases, the RMS is equal to…
Sebastian
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High audio frequencies in television broadcast

I would like to know if in television broadcast high end audio frequencies are transmitted e.g. frequencies higher than 14 kHz. What is the cut off audio frequency of transmission in television broadcast? I am preparing a report (for research)…
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How to change volume of a PCM 16 bit signed audio?

I know I can multiply samples, then clip but perceived volume is non-linear for humans. Can you please help with a formula.
apocalypse
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Teager's Energy Operator

Does anyone know how to find information on the derivation (rather than the definition and application) of Teager's Energy Operator, both for the continuous and sampled case. I have Kaiser's early papers "On a simple Algorithm to calculate the…
user7944
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Calculating bpm from machine sound (not music)

I have a hydraulic breaker on a excavator that hammers with a dynamic bpm. I have recorded this sound so that it is in a mp3-file and would like to determine the momentary bpm for the length of the file. I have tried using processing with beat…
blom
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How to create a sine wave that transitions through frequencies and returns to phase

For an auditory psychological experiment, I need to create a sine wave, such that at a given point the frequency of the wave will rise smoothly, and descend back to base frequency. I need it to return in phase with a second sine wave which is a…
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