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Feedback Comments on Sound

by Ron Kurtus

A total of 189 comments and questions have been sent in. They are listed according to date.

List of next 10 letters




Sound Echoes Idea of using echoes with the Titanic USA
Noise Reduction Will installing tile increase room noise? USA
Noise Cancellation I have a ringing in my ears USA
Sound Waves What is a longitudinal wave? Belize
Noise Cancellation Reducing noise from highway USA
Noise Cancellation Fishing boat engine is too loud Canada
Noise Reduction How we can reduce the noise? India
Sound Waves Ultrasonic devices India
Sound Speed in Gas Calculations on echoes Ghana
Sound Waves What is the speed of a sonar signal in water? Philippines

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First 10 letters

Idea of using echoes with the Titanic

Topic: Sound Echoes


April 16, 2012

Consider the Titanic, which hit an iceberg and sank 100 yrs. ago:

The Titanic had been warned about icebergs in the area. If The Titanic had posted "listeners" near the bow, and sounded short blasts on it's foghorn, at appropriate intervals (15-30 seconds), the echos from icebergs would have been heard by the "listener" and the Titanic could have taken evasive action.

This would have been using a crude form of SONAR.

Please comment. Thank you in advance for your reply,

Joseph - USA



One problem with icebergs is that they are usually 90% below the waterline. However, with a large iceberg, there might have been enough above water to create an echo, like you suggest.

Another problem with trying to hear an echo from an iceberg or even another large ship is the shape is typically not flat, such that the echo would bounce directly back to the ship. Any curvature in the iceberg would spread out the echo.

However, your idea is clever. I don't think using humans to hear such echoes has even been applied.

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Will installing tile increase room noise?

Topic: Noise Reduction


February 6, 2012

"Will removing carpet from a room and installing ceramic tile increase noise?
This room is 3500 square feet.
If so what percent will sound increase?

Buster - USA



Carpeting does absorb some of the sound in a room, while ceramic tile does not. This would add the the noise in the room, especially such a large room. To compensate, it is good to have sound absorbing materials on the walls and ceiling. Drapes help out. Acoustical tile on the ceiling helps. Furniture will also reduce the noise.

I don't have statistics on the increase of sound. In fact, it would be difficult to predict. An acoustical engineer might have to visit to be able to give a real number.

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I have a ringing in my ears

Topic: Noise Cancellation


February 6, 2012

I have a ringing in my ears which sounds like a single high frequency tone. If i could figure out what the frequency is of the tone that i'm hearing, could I use a tone generator to produce the opposite frequency and try to cancel out the tone in my ears? How do i calculate the value of the opposite frequency?

Jeff - USA



It sounds like you have tinnitus, which is a condition that many people get as they become older, especially if they have been exposed to loud sounds. Since it is a function of the nerve circuitry in the inner ear, you really can't cancel it out. Some people use white noise generators to mask the sound, if it becomes too annoying.

Tinnitus is related to Meniere Disease. The article has some information on it and possible solutions.

Best wishes on dealing with the ringing. It can be annoying if you focus on it.

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What is a longitudinal wave?

Topic: Sound Waves


October 12, 2011

Sound is a longitudinal wave that is produced by vibrating sources. Sound waves emitted from two sources are found to be vibrating in phase. Explain what is meant by the terms - longitudinal waves; vibrating in phase

Marcelo - Belize



Longitudinal waves go back-and-forth in the direction of motion. On the other hand, water waves are transverse waves and go up and down, perpendicular to the direction of motion.

If two waves of the same wavelength are moving such that their peaks arrive at a point at the same time, they are in phase. An example could be two water waves moving parallel with their peaks next to each other.

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Reducing noise from highway

Topic: Noise Cancellation


September 14, 2011

My patio is about 65 ft from a highway soundwall that is about 15 ft high. The traffic noise if very loud. Is there anything that will deaden the sound, that can be used outside on the patio?

Jay - USA



Unfortunately, some of the road noise is going over the sound wall and curving downward to your patio area. A row of high shrubs can often be used to help reduce the noise.

For more information, see Noise Reduction of Sound.

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Fishing boat engine is too loud

Topic: Noise Cancellation


April 18, 2011

I work on a fish boat that is powered by a deisle engine which is quite loud. Is there some thing out there that would cancell the noise without wearing a head set. The cabin where you would want the cancelation is about 10' X 10" X 6' high



paul - Canada



That type of noise is a major problem. Manufacturers could do a much better job on insulating this type of noise.

The only thing your could do is to reduce the noise through installing noise reduction insulation around the engine or in your cabin.

Some sites to check are: Soundproofing - Marine Engine Noise Reduction Listings

Marine Noise Reduction Systems

Soundproofing Solutions for the Marine Industry

I hope that helps

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How we can reduce the noise?

Topic: Noise Reduction


April 9, 2011

Sir,I want know how we can reduce the noise by adding certain type of noise?

Arvind - India



See the lesson on Active Noise Cancellation. It explains how a reproducing the opposite sound can cancel out the sound of the noise.

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Ultrasonic devices

Topic: Sound Waves


March 22, 2011

I want to know that if is any device that can produce a sound of 20000Hz with varying intensity.and i also want o know that whether such a sound of high intensity can cause our ear to blast and consiquently loose our body balance
Thanks in advance

Nikhil - India



Sound above 20,000 Hz is called ultrasound. There are many devices that use ultrasound, including ultrasonic cleaning and medical ultrasound viewing.

Frequency is not intensity, which would be loudness to a person. Since a person cannot hear above 20,000 Hz, the ear does not react to it. However, a loud, high frequency sound has enough energy to possibly cause damage.

Ultrasonic weapons can disable a person.

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Calculations on echoes

Topic: Sound Speed in Gas


February 19, 2011

Calculations on echoes

Samuel - Ghana



See our lesson on Echoes

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What is the speed of a sonar signal in water?

Topic: Sound Waves


February 16, 2011

what is the speed of a sonar signal in water with a frequency of 1000 Hz and a wavelength of 1.5 m?

chadrinka - Philippines



The speed of a waveform equals its frequency times its wavelength. Speed equals 1000 Hz * 1.5 m = 1500 m/s.

That is close to the official speed of sound of: 1,484 m/s.

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