22 replies to this topic

[Caldor]

My understanding is that psychoacoustic effects are still debated. Do we have any scientifically conclusive tests/data prooving it? The bits Ive read are critical of the idea.

[Pulse-R]

like anything, test results can be used to prove anything.
depends on how you do the test, how you measure the results and how you interpret the measurements.

[Jack88]

haha its like i can hear thos electric bug repeler things that u plug into the power point and they emit a frequencie that only the dam bugs are soposed to hear!they drive me absolutly nuts.

[xen]

I studied sound at the Con up here in Qld, and we had a very cool research project we did every year. We could do it on anything at all we wanted. People came up with some great stuff.

One year some guys did a bunch of listening tests with random people, to determine how high a frequency people were able to hear the difference between a sine wave and a sawtooth wave. Turned out people could pick them apart at 15kHz.

The point was that sine waves and sawtooth waves should be identical up to the first harmonic - which is double the root frequency. In other words, according to theory at least, people were hearing things at 30kHz (and they were neither small children, nor dogs).

I've thought about this a lot over the years, and really wish i knew more about their methodology, because it's a pretty damned interesting result ;-)

Edited by xen, 23 March 2006 - 08:40 PM.

[pundit]

xen, on Mar 23 2006, 08:39 PM, said:

I studied sound at the Con up here in Qld, and we had a very cool research project we did every year. We could do it on anything at all we wanted. People came up with some great stuff.

One year some guys did a bunch of listening tests with random people, to determine how high a frequency people were able to hear the difference between a sine wave and a sawtooth wave. Turned out people could pick them apart at 15kHz.

The point was that sine waves and sawtooth waves should be identical up to the first harmonic - which is double the root frequency. In other words, according to theory at least, people were hearing things at 30kHz (and they were neither small children, nor dogs).

I've thought about this a lot over the years, and really wish i knew more about their methodology, because it's a pretty damned interesting result ;-)

Play a sinewave at 20khz and most people (apart from those under about 12) probably won't hear anything.
Play a square wave at 20khz and many more will notice something due to the harmonics. Even if they can't hear the fundamental certain individuals will sense something even if they don't perceive it as sound. It may simply make some of them feel uncomfortable or agitated without even knowing why.

I can hear 80khz! Well to be more to the point I heard the effect 80khz switchmode noise had on frequencies in the audible range... BAD!!

Intermodulate two frequencies and you don't just get the combination of those two frequencies alone... new frequency by-products can result.
Even frequencies well outside of the range of human hearing can have audible results when combined with those within the audible range. This can be both good and bad. Harmonics that cannot be heard in isolation intermodulate with, and add characteristics to those sounds we can hear. Wide bandwith audio systems (SACD etc) potentially provide a greater degree of fidelity (with suitable wide bandwith recordings). However poor shielding, filtering, power supply rejection and common mode rejection can cause unwanted ('out of audible range') noise to enter and have a corresponding negative effect on the sound we can hear.

Would you feel completely comfortable starting a recording project using totally unbalanced equipment (even mic lines) even if you couldn't hear any audible noise with the monitoring cranked right up?
I know I wouldn't!

Edited by pundit, 29 May 2006 - 09:34 PM.

[Riley]

how do i choose which frequencies i use? i have a 7 band PEQ (7 high and 7 low i think) and there are alot of different frequencies i could use....how do i choose?

or is it really just dependant on my car ?

[Pulse-R]

it depends on your taste, rather than the car.

you need to try each setting and see how it changes the sound, then leave it where you like it best.

[MaFi0s0]

I did an online audiogram, so did my cousin, and strangely we couldn't hear 18KHz but we could hear 20KHz.
http://www.digital-r...udio_test_p.cgi