Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [sound]

Audible vibrations transmitted through air or other medium

466 questions
41
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9 answers

How can "purely" electrical circuits emit sound?

Moving membranes or piezoelectric materials obviously produce sound waves, but how can "purely" electrical circuits such as transformers or DCDC choppers (and others) often have an audible noise? Is the material microscopically expanding and…
Mister Mystère
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Why should I use a logarithmic pot for audio applications?

Just got really curious about it reading this answer from Spehro Pefhany. There Spehro comments that one should use a logarithmic pot for audio applications. So I googled for it. The best article I could find was one titled "Difference between Audio…
Ricardo
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5 answers

I've become an electrical conductor for my headphones... but how?

So I have a pair of Bose noise-cancellation headphones that I plug into my keyboard every night to charge them (via my keyboard's USB port). My keyboard happens to be a metallic Apple keyboard. You will see why this may be important to note…
GDP2
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6 answers

Why do high voltage power lines hiss when it's raining?

I noticed when walking home the other day that the high voltage (200kv I believe) lines running through here were hissing in the rain. What is causing them to hiss?
pfyon
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11 answers

What is the difference between a buzzer and a speaker and are there any other basic electric/electronic things that output sound?

I am playing with a speaker and a microcontroller and in some documentation the speaker is called buzzer. The assistant told us that is a mistake and we are dealing with a speaker. I am wondering what exactly is the difference between the two,…
yoyo_fun
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Why do my speakers make a noise when my cell phone gets a call?

It's a very common sound but I've never thought to question why it happens.
Sean Southern
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12 answers

Polyphonic sounds from a microcontroller?

I can make monophonic sounds by toggling a single pin (at a varying rate) connected to a piezo buzzer. How can I generate two mixed audio signals in software to create polyphony? Here's the code I'm using to play a simple tune. #define F_CPU…
Toby Jaffey
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5 answers

What is the simplest sound generating circuit?

I'm relatively new to electronics, and have no formal training other that what I picked up through my electrical engineer father. I solder well, can read schematics, have assembled kit projects with a rough understanding of how all the parts work,…
dwwilson66
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3 answers

How to convert volts to dB SPL

I am taking input from an electret microphone amplified using LM358 amplifier from my PIC16F877A's ADC unit. I am getting the readings in volts from the ADC which ranges from 2.5V to 5V. How can I convert these readings into dB?
user35456
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2 answers

What is the coil for in these cheap tweeters?

I disassembled a cheap tweeter because I wanted to use only the inner part of it since it is just about 5mm tall (1/4 inch). I thought the coil that surrounds it was just a cheap inductor to "short out" low frequency and protect the tweeter. Turns…
Jahaziel
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2 answers

Where have the 8 bit sound chips gone?

I know it's 2014 and you can get an MP3 player and 40 bazillion terabytes on a microscopic chip. But I want to build a 6502 based retro computer and, in a perfect world, I would order up about 200 SID chips. Anyway, are there any mass produced…
cbmeeks
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If we use potentiometers as volume controls, don't they waste electric power?

I recently heard that we use potentiometers to reduce the volume levels in audio devices. Will it waste electrical energy?
Abin Latheef
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What is IP and NK transformation (seen on earphones)?

By the side of my earphones, there's a switch that flips between two initials, IP and NK. This Quora question suggests that this is the IP / NK transformation, which somehow makes the earphone universal. What exactly is this and what is it for? NB:…
Heisenberg
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How do I detect the pattern of the knock on a door, and use it as a signature to unlock a door?

How do I detect the pattern of the knock on a door, and use it as a signature to unlock a door?
littlebirdceo
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Circuit that measures the speed of sound in concrete

I need a circuit to measure the speed of sound in concrete to 1μs or better. This is for a school demonstration where students who study construction will use this circuit to measure the speed of sound in a sample of concrete to determine the…
FlaSh
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