Oscilloscope question

S

samich17

New member
The distance a sound, as seen on an oscilliscope, varies from the center line is called its ________ and it relates to its __________.


my take is that the answers are "amplitude" and "volume", because the further away from the center line it travels, the louder the signal would be.

what do you think?
 
could be offset and phase? The question seems somewhat open ended though. Your guess is as good as mine.

Brandon
 
Amplitude and volume indeed...

Offset is the mean value. If you have a sinewave that evolves around 1 (going from 0 to 2) then your offset is 1.

Phase is too difficult to explain in words, so I'm not gonna explain it. :p
 
thanks guys...i don't believe i have to take exams with this apprenticeship, although i guess it is a good thing...


The actual distance a wave travels in a medium is called its __________. (wavelength)

The speed at which a wave travels through a medium is called its __________. (frequency)


Harmonics of various intensities within a sound wave determines __________. (timbre)


Due to the "un-flatness" of our ear, the best monitoring level for mixdown is _________. (85dB SPL)


Three types of interaction effects in our ear are:

a.___________ (Collection of sound pressure)
b.___________ (Conversion of sound pressure into mechanical vibrations by way of the hammer, anvil and stirrup)
c.____________ (Responding of hairs to different frequencies along the Cochlea which gives the sensation of hearing)



Our two ears and brain system use 3 ways to locate the direction of sound, what are they?

a.____________ (interaural intensity difference)
b.____________ (interaural arrival-time differences)
c.____________ (the effects of the Pinnae (ridges of outer ear))



These are some sample questions and my answers to them...please check them over and give opinions and other feedback...greatly appreciated
 
Those are some good answers to some lousy questions.

The distance a wave travels in a medium is simply the distance it travels.... I mean, a wave in the ocean can travel from the US to China, through the water. It has nothing to do with the wavelength. I think they are TRYING to ask about wavelength but wavelenth is defined as the distance between wave crests.

Same deal with the frequency question. Frequency is defined as the wave crests that pass a point per time. Usually in waves /sec or Hz. The speed the wave travels throuh a medium has nothing to do with it's frequency. Light waves travel at 186,000 mi/s in a vacuum (no medium at all!!) It has nothing to do with the frequncy, all frequencies travel the same speed.

The other questions are a little weird too.

Who's giving this exam??
 
The actual distance a wave travels in a medium is called nothing.

The speed at which a wave travels through a medium is called its travelling speed.

These 2 questions are complete nonsense. If the dude really asked this, he is not in a position to teach you.
 
Nonesense

Questions 1 and 2 are nonesense. I see what he's trying for in question 1, but 2 what the hell.

What school are you going to? It is shit like this that gives audio engineering schools a bad rap.
 
samich17 said:
thanks guys...i don't believe i have to take exams with this apprenticeship, although i guess it is a good thing...


The actual distance a wave travels in a medium is called its __________. (wavelength)

The speed at which a wave travels through a medium is called its __________. (frequency)
Click to expand...

Im not sure these questions are worded correctly. The frequency is the number of cycles per second a wave completes a 360 degrees on a phasor. Crest to Crest measurement is the wavelength. Frequency and wavelength are related. The speed is tricky because the types of wave vary. Radio waves travel at the spped of light, therefore the wavelength changes but the speed is constant. Short wavelengths have higher frequencies. The distance from the zero line to the crest is usually called intensity (energy), which can be volume or voltage, I prefer db voltage type references. Volume to me is a subjective term, like loud or soft. Intensity: The amount of energy flowing per second through a unit of area in a plane normal to the direction of propagation. Clear as mud right :0)

Peace,
Dennis
 
for real guys. i've been saying these same things to myself over and over..the questions are worded very strange, everybody has been telling me so..the main book i am reading for the program is called, Modern Recording Techniques 5th Edition and the program is called Recording Connections...it is better than college taught classes on the subject, because i am training one on one in a real recording studio, but so far, the "exams" have proven to be a lame. what should i think of this? the program is completely legitimate..i've called numerous people who have completed the program and went on to get employment. i don't know...it might get better..the people who word the questions might not have anything to do with engineering, thus making fools of themselves and confusing the shit out of me...thanks for the comments.
 
Amplitude is not the whole story to Volume. Volume or 'loudness' is also frequency dependent. Your ear/brain more approximately responds to the amount of energy in a sound wave rather than just it's amplitude. A high frequency wave has more energy in it than a low frequency wave with the same amplitude and will, therefore, sound louder.

And like I said, volume perception is only approximately a function of power. The perceived loudness at a given power is not flat across the frequency spectrum. And to further complicate things the shape of the curve changes as the power changes - i.e. the perceived color of the sound changes as the volume changes.

barefoot
 
barefoot - thanks for responding and for the information...based on what you said, what would think the answer would be then to the original question?? thank you very much
 
samich17 said:
The speed at which a wave travels through a medium is called its __________. (frequency)
Click to expand...
This one is wrong. I'm not certain what they're looking for here. Maybe "sound velocity", but velocity implies direction as well as speed.

Frequency has no dependence on the speed of sound in the medium.

barefoot
 
oh, i apologize...that wasn't the question i was talking about..

the question is

The distance a sound, as seen on an oscilliscope, varies from the center line is called its ________ and it relates to its __________.

thank you
 
samich17 said:
...based on what you said, what would think the answer would be then to the original question?? thank you very much
Click to expand...
Your answer is right. Amplitude does relate to volume. I was just saying it's not the whole story.:)

barefoot
 
good, i am glad it is right, but it still feels written poorly. i expect more from a professional recording connection program. thanks for responding
 
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