Questions tagged [sound]
26 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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5
votes
2 answers
How to build apartment floors/ceilings to not transfer sound?
How do new apartment buildings build their floors/ceilings to prevent the transfer of sound between people living above/below each other?
Note: I'm not asking about how to soundproof an existing structure. I'm asking how a structure should be…
Michael Altfield
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4
votes
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
votes
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
votes
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
Designing a siren to vary pitch with port width/pattern. Advice needed
Background: I am trying to design a multi-pitch port siren with one central shaft at 3300 rpm. I've calculated the number of ports needed for each frequency to be n = f(60/rpm). This approach gives me fractional n for many values, which I want to…
Jordan Iversen
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1
vote
2 answers
High voltage wires
We have bought a house near high tension wires (at a distance of around 20m). Will it be noisy during the rains, and more importantly will the ionization increase the risk of cancer?
Shrey Iyer
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1
vote
3 answers
Do sound waves caused by a vibrating machines correlate to the vibration waves of the machine itself?
I'm a computer engineer, so please excuse my lack of mechanical knowledge :).
We have a machine that has large electrical motors causing massive amounts of vibrations, the machine also consists of many frames and large plates. Due to this vibration…
Rikus Coetzee
- 11
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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
vote
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
votes
0 answers
What are acceptable levels of sound isolation in apartment buildings? (ISO 16283)
What are acceptable levels of sound isolation in apartment buildings, using the results from ISO 140 ISO 16283?
This, of course, differs by country/region/city/etc. Some locales may not have any laws requiring new multi-family buildings to meet some…
Michael Altfield
- 225
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0
votes
1 answer
How to design an analog filter for an acoustic sensor
It's been a while since I've done this, but I have an acoustic sensor meant to detect low frequency sound waves attached to a 5/32" ID hose that leads out to open air. I seem to recall from my grad school days that there's a relationship between the…
Engineero
- 103
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0
votes
0 answers
Will circular or elliptical torus shape have a nigher natural frequency?
Given 2 metal shapes which have the same mass and identical material, a circular torus and an elliptical torus:
which of these two shapes would likely have the higher natural frequency, if the mass and material is the same in both?
James
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0
votes
2 answers
Are Apple Airpods capable of producing 165 decibels of sound?
Inspired by this article, where a Texas family claim that an "Amber Alert" on their son's Airpods caused his eardrum to…
0
votes
2 answers
Most sound proof earmuffs in the world
What soundproofing material can I replace the foam in my Sthil earmuffs with to block out leaf blowers completely. I mean the absolute highest power blackout capability possible.
Crazy ideas welcome, e.g. fill the cups with silicone etc..
Julian
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