Natural Science Forum / Physics / Acoustics / January 2007

I need to know what are the effects of sound alteration via dsp
(reverb, echo, chorus, flanger...), filtering and equalization on
persons. I searched with google and google Scholar but found very poor
results. Does someone know where can I find such information?

I'm looking for more informations about how recorded speech changes if
speaker is in same room, but at a distance of few meters. Also I'm
interested how recorded speech changes if there is acoustical obstacle
between speaker and microphone. I know that reverberation effect appears,

I've been out of acoustics and this group for many years.  Glad to see
it still so active.  In one of my moves I've lost a disk with a program
I want to use.  It was a free program called Community Noise Model
(don't know why) from

What is Wave characteristics ?
" Waves transfer energy without any matter being transferred.
" Waves travelling along ropes, springs or the surface of water set
up regular patterns of disturbance...... detail at

I want to send audio signals through the ground and wonder how far I
can expect the sound to travel , Assume for exmple that I have a 10
watt source coupled to the ground via a loud speaker that is in contact
with the soil ( not asure how do this ! ). The big ? is how does the

When you whistle, what is happening ? Is it a helmholtz resonance ?
Steve M

can anyone here let me know about how to reduce printer noise which is
60db(current) to 45db or less....
these are some details.....
when tested , the background noise is 34db, 56db when

starting ultrasonic sensor project, would like to ask:
1) has any ideas how to over come turbulance problem? turbulance source
is 2 meters from sensor. Target to be detected is 11 meters away.
2) I am searching the web for days, but didn't find much, maybe you can

I'm new here and still learning acoustics. One of my friend asked me a
question : if we're yawning while listening to music, it seems the
perception is different (more bass at certain frequency), why is that?
I hope it's not too stupid to be asked, but I guess this happens

Reflection of light and sound
" Sound waves are reflected or bounced from hard surfaces.
" An echo is a reflection of sound........
Detail of article is at.......

Good day!
I have a question regarding sound sources. If I have a horn speaker
with a high directivity and I stand 500 ft away from it, can I consider
it as a point source?

Think twice before you refer to someone on the internet, by name, as a "gay commie perverted pedophile."  Doing so could cost you a lot of money.

I'm interested in finding the reverberation time for an acoustic signal
in a tank filled with water, but confused about how to find it.  I know
that the reverberation time is the time required for the sound to decay
by 60 dBs, but I'm confused as to how to actually calculate this.

Does anyone here know the status of the ftp.ircam.fr site (or who I
could contact to obtain the status)?  I've been unable to make a
connection to gain access to data there despite it supposedly being a
public archive.