why we cannot heard echo in small room?
you know that echo is refecting back of sound . if the sound presists in our ear for more than 0.1sec than echo is heard . more over temperature also dertermines it . if the temp. is more speed will increase and distance could be reduced of decreased also .
for more details refer to the ncert class 9th or dinesh super simplifiied science physics class 9th.
you may also consut this to your subject teacher or tution teacher .
if you paid meber on merit nation you can consult the study material of class 9th cbse chapter : sound
The first one is right. There are reflections, but they arrive quickly as the distances are small. You notice late reflections as echoes not early reflections.
Insulation has nothing to do with it, acoustic absorption would alter the loudness of the reflections and this would have an effect. A large room can be treated with a lot of acoustic absorption and this too would have few reflections and no perceived echo.
X= 332m/s *.1s=16.6m
speed of sound=340m\sec
let the minimum distance of hearing an echo be y
340\2 X 1\10 =340/20 IS EQUAL TO VELOCITY X Y/2
THEREFORE THE MINIMUM DISTANCE=17M
There are several ways we perceive sounds in a room which our auditory system integrates into a whole experience of the sound.
1) Direct sound - This is the sound arriving direct to your ears with no reflections
2) Early reflections - The first direct reflections from the room. This helps us to localize the sound for frequencies over about 1kHz. We typically don't perceive this as a different sound to the direct sound because the time interval is too short (up to about 30ms)
3) Reverberation - This is kind of a wash of reflections bouncing all over the room.
4) Echo - If the size of the room is large (or the reflective wall far away) the reflections will be far enough apart that we can perceive them as seperate events and a true echo (over about 80-100ms is probably enough time)
In a small room all reflection events happen so quickly due to the small space that the early reflections/reverb stages are kind of rolled into one and the size of the space is too small for an echo.
The reverb time (measure of how quickly the reverberant sound drops 60dB) is a lot less for small rooms because more reflections happen in a short space of time and the sound waves get absorbed quickly.
Sound does echo inside a room but you might not notice it much for two reasons.
Firstly the time for the echo to return is very small so you will not hear a long sound repeated as an echo, instead you will get a resonance type echo, like when you sing in the bathroom.
Secondly most rooms are full of soft furnishings that quickly absorb the sound and damp the resonance.
If you are in a large room with no furnishings and you clap once loudly you will certainly hear the echo rebounding rapidly off the walls.IF HELPED PLZ . THUMBS UP
Ans) Echo is defined as one time of reflection of sound from a cliff or building or sound reflecting surface i.e. Mountains.
The factors which is essential for the production of echo is what is minimum length required so that echo can be produced is 17.2m.
So if echo production had to take place then the difference between source of sound i.e. a boy and a sound reflecting surface i.e. walls/mountains /room is 17.2m ....
If distance is less than 17.2m then echo will not be produced
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