Engineering Stack Exchange
Engineering Stack Exchange

Questions tagged [sound]

10 questions
7
votes
2 answers

Simplest way to reduce low frequency noise from windows

Could you please advise the simplest method to reduce low frequency noise from windows? The problem: Somewhere outside there is a source of noise with frequency of 166 Hz. I can’t neither find nor remove it. This could be ventilation hoods on other…
Damir Tenishev
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4
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2 answers

Why does the frequency of a bottle filling up changes?

Today as I was filling up a bottle of water, and I could hear the distinctive change in pitch that signals that the bottle is near filling up, I started wondering what equation determines the frequency of the sound. More specifically, I suspect this…
NMech
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2
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1 answer

What is the mechano-acoustic effect of off-centering the black paste on tabla-drum skins?

Tabla is a musical instrument composed of two drums, the Bayan (left on picture) and the Dayan (right on picture). A unique feature of the tabla is the tuning [black] paste called the gab, applied to the center of the dayan and off-center on the…
Noil
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2
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2 answers

How to convert the velocity field to a pressure field for obtaining the sound level?

I am studying jet mixing noise and I am given a velocity field, with $V_x$, $V_y$, $V_z$ in the Cartesian coordinates. I wanted to know if there is a method by which I could find some information relating to the sound level produced from the…
fidafa123
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1
vote
1 answer

Confusion over textbook formulae for directional characteristics of sound sources

I'm currently reading Olson's Elements of Acoustical Engineering, in which formulae are given for the directional characteristics of various arrays of sound sources, all of which are stated in terms of ratios $R_\alpha$ of pressure at a given angle…
apk
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1
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2 answers

How do I remove outliers in measured sound pressure levels data?

I have measured sound pressure levels (24 h sampling at 25600 Hz) data for many days. The focus of measurements was on road noise, which is a dominant source of noise in the measurement setting. However, there were occasional "disturbances", such as…
khajlk
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0
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3 answers

Can two microphones placed within centimeter distance together measure a distance of the sound source?

I have placed two microphones placed within 1 or 2 cm distance. They can receive and record sounds around them. I want to detect the distance of the sound source (specially human voice) and the direction of the sound source using those microphones.…
Sazzad Hissain Khan
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0
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1 answer

IC engine Exhaust gases flow simulation through absorption type muffler

How is the exhaust gas flow through the absorption type muffler. I am interested to know how the exhaust gases enter the absorption material(fiber glass) before leaving through the end pipe. What makes the exhaust gases to enter the fiber glass for…
Sonali Pansare
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0
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3 answers

Respirator mask that transmits sound waves

If one had to design a respirator that would have the minimal sound distortion, and allow to communicate normally (one-on-one at least), how would one do it? I wear powered respirators (PAPR) and valved respirators at work, 8-10 hrs a day. This is…
runcyclexcski
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How to use Spectroid app to measure low frequency vibrations?

I need to measure how low frequency (vibration) changes when going through different materials. The only possible way I found is by using Spectroid app. However, I have no idea of what settings to set up. Test environment would be: Subwoofer,…
NightRider
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