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### Re: Sounds of Music C

Posted: March 19th, 2019, 5:06 pm
EmiliaM wrote:What is a celesta
It's sort of like a piano where instead of strings the hammers strike metal keys.

### Re: Sounds of Music C

Posted: March 23rd, 2019, 7:54 pm
Does anyone know what app or device will be used at most State Tournaments (particularly MI) and Nationals for pitch and volume tests? I've found that different devices and apps can give very different results, and I just want to make sure we're practicing as with the same one as event supervisors will use. Anything helps, thanks!

### Re: Sounds of Music C

Posted: March 24th, 2019, 4:08 pm
timwu0 wrote:Does anyone know what app or device will be used at most State Tournaments (particularly MI) and Nationals for pitch and volume tests? I've found that different devices and apps can give very different results, and I just want to make sure we're practicing as with the same one as event supervisors will use. Anything helps, thanks!
Google Science Journal is often used although I'm not sure whether it will necessarily be used at your state tournament or nationals.

### Re: Sounds of Music C

Posted: March 24th, 2019, 4:19 pm
wec01 wrote:
timwu0 wrote:Does anyone know what app or device will be used at most State Tournaments (particularly MI) and Nationals for pitch and volume tests? I've found that different devices and apps can give very different results, and I just want to make sure we're practicing as with the same one as event supervisors will use. Anything helps, thanks!
Google Science Journal is often used although I'm not sure whether it will necessarily be used at your state tournament or nationals.
From what I've heard nationals will not use Science Journal.

### Re: Sounds of Music C

Posted: March 25th, 2019, 8:39 am
wec01 wrote:
timwu0 wrote:Does anyone know what app or device will be used at most State Tournaments (particularly MI) and Nationals for pitch and volume tests? I've found that different devices and apps can give very different results, and I just want to make sure we're practicing as with the same one as event supervisors will use. Anything helps, thanks!
Google Science Journal is often used although I'm not sure whether it will necessarily be used at your state tournament or nationals.
At my Michigan regionals they used Sci Journal, but I'm not sure what they'll do for states because it's not being used at nats.

### Re: Sounds of Music C

Posted: March 25th, 2019, 9:32 am
SHASO2018 wrote:
wec01 wrote:
timwu0 wrote:Does anyone know what app or device will be used at most State Tournaments (particularly MI) and Nationals for pitch and volume tests? I've found that different devices and apps can give very different results, and I just want to make sure we're practicing as with the same one as event supervisors will use. Anything helps, thanks!
Google Science Journal is often used although I'm not sure whether it will necessarily be used at your state tournament or nationals.
At my Michigan regionals they used Sci Journal, but I'm not sure what they'll do for states because it's not being used at nats.
If it was used at regionals there is a decent chance it will be used at states since the event supervisor could easily be the same person.

### Re: Sounds of Music C

Posted: March 30th, 2019, 7:57 am
What resources are you guys using for studying decibels? I'm trying to help my team figure it out but it's super confusing...

### Re: Sounds of Music C

Posted: March 30th, 2019, 8:30 am
agentm wrote:What resources are you guys using for studying decibels? I'm trying to help my team figure it out but it's super confusing...
The wikipedia page might be helpful and there's also a hyperphysics page on it: http://hyperphysics.phy-astr.gsu.edu/hb ... ntens.html

Basically, the point of decibels is to measure sound intensity in a way that is closer to how we perceive loudness, which is why it varies logarithmically with W/m^2. So if you hear a sound as twice as loud as another, the first one is roughly twice the number of decibels, not twice the W/m^2.

Because decibels are supposed to be more related to human hearing, that is also why $I_0$ is the value that it is. $I_0$ is roughly the minimum sound intensity humans can hear, so if the intensity is at $I_0$ (so if $I=I_0$), then $10log(I/I_0) = 10log(I_0/I_0) = 10log(1) = 0 dB$. This makes 0 dB the minimum intensity humans can hear.

I'm not sure what part of it specifically is confusing you, but I hope this sort of general overview helps.

### Re: Sounds of Music C

Posted: March 30th, 2019, 11:06 am
wec01 wrote:
agentm wrote:What resources are you guys using for studying decibels? I'm trying to help my team figure it out but it's super confusing...
The wikipedia page might be helpful and there's also a hyperphysics page on it: http://hyperphysics.phy-astr.gsu.edu/hb ... ntens.html

Basically, the point of decibels is to measure sound intensity in a way that is closer to how we perceive loudness, which is why it varies logarithmically with W/m^2. So if you hear a sound as twice as loud as another, the first one is roughly twice the number of decibels, not twice the W/m^2.

Because decibels are supposed to be more related to human hearing, that is also why $I_0$ is the value that it is. $I_0$ is roughly the minimum sound intensity humans can hear, so if the intensity is at $I_0$ (so if $I=I_0$), then $10log(I/I_0) = 10log(I_0/I_0) = 10log(1) = 0 dB$. This makes 0 dB the minimum intensity humans can hear.

I'm not sure what part of it specifically is confusing you, but I hope this sort of general overview helps.
It's worth noting that decibels can denote sound pressure as well as sound intensity and so you should have reference values for both (one in pascals and one in watts per square meter).

### Re: Sounds of Music C

Posted: April 1st, 2019, 4:48 am
wec01 wrote:
agentm wrote:What resources awe you guys using fow studying decibels? I'm trying to hewp my team figure it out but it's super confusing...
The wikipedia page might be helpful and thewe's also a hyperphysics page on it: http://hyperphysics.phy-astr.gsu.edu/hb ... ntens.html

Basically, the point of decibels is to measure sound intensity in a way that is closer to how we perceive loudness, which is why it varies logarithmically with W/m^2. So if you hear a sound as twice as loud as another, the fiwst one is roughly twice the numbew of decibels, not twice the W/m^2.

Because decibels awe supposed to be mowe related to human hearing, that is also why $I_0$ is the value that it is. $I_0$ is roughly the minimum sound intensity humans can hear, so if the intensity is at $I_0$ (so if $I=I_0$), then $10log(I/I_0) = 10log(I_0/I_0) = 10log(1) = 0 dB$. This makes 0 dB the minimum intensity humans can hear.

I'm not sure what pawt of it specifically is confusing you, but I hope this sort of genewaw overview helps.
We never studied logs, so that's the hardest part. I'm still a little unsure of the difference between sound intensity, sound pressure, and sound pressure level. Like...why are there three different ways of describing the same thing? Also, my team saw a question on an invite test about how many decibels something was "twice as loud" and the answer apparently wasn't twice the decibels. Maybe it was "twice as intense"? Does that make a difference?

Also.....for some reason my browser is changing r's into w's and I can't figure out what the heck is going on. It's actually kind of amusing.