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View Full Version : a few questions on acoutsics and echo



llamafarmer
01-18-2012, 05:17 AM
Can't seem to find the answer in the Great Googleverse so thought I'd try here:

how would the acoustics of an entirely unfurnished marble corridor be (no carpeting, no rugs, no furniture or ornaments of any sort), if everything was marble (not just the floor)? Say it was 2 meter in width, 3 meter in height, and 50 meter in length. As it's bare there would obviously be more echo and resonance than if the place were furnished, so what exactly would that be? Greater echo? Longer sustenance of sound? Sorry I don't know the technical terms.

If one person were to walk down the corridor, completely alone, saying nothing but perhaps coughing, what would happen to the sound of their footsteps and cough? With the corridor only being extensive in length would the sound just dissappear down it, or would it still bounce off the walls?

Thanks in advance to anyone who can help. :)

Drachen Jager
01-18-2012, 05:46 AM
The footsteps and cough would be echoed back and forth forming almost a 'hall of mirrors' effect only with audio. It would be pretty creepy I think.

Kenn
01-18-2012, 05:11 PM
The corridor is too short to get an discernible echo and you would get a reverb effect - it's sort of an extended time taken for the sound to die away. If you've ever been in a church or cathedral and heard somebody slam a door or drop something, then it's the same sort of effect. The walker could also set up a resonance effect as they walked down the corridor (depending on fast they were going).

An important factor is that marble is very hard and inflexible, so the sound would have to come from the shoes. If they are rubber soled, then they will be pretty much silent. Otherwise, it might be a clicking type of sound associated with steel tips.

The cough would have a shorter reverberation time, because of its lower frequency. In effect, it would be probably drowned by the noise from the shoes.

llamafarmer
01-26-2012, 09:31 PM
Thanks guys! Apologies for the late response; seems I forgot to subscribe to this thread so I received no notifications and thus assumed no-one had replied.

Mark G
01-26-2012, 10:06 PM
You're basically talking about an echo chamber. With nothing to disrupt the wave patterns, every sound you make will bounce off every surface. Try walking around in a new construction house with no carpet, or (this is perfect) a pedestrian tunnel in an urban area. Though tunnels are typically cement or cement/tile. Polished marble would probably echo more.

Sources: personal experience and "physics of music" class.

llamafarmer
01-26-2012, 10:18 PM
Perfect :) Thanks Mark!