Decibel range

Smallest audible sound is 0 dB and a sound 10 times more powerful is 10 dB. Noise levels based in decibels is linear, which means that noise levels cannot be added together directly. The unit of decibels is based on a power of 10 and the decibel range varies depending on the sound of the object and the environment it is in.

The threshold of hearing in this chart shows the decibel range in different locations and how loud it is to the human ear.

Loudness

We found the decibels of loudness and different sounds. We found that anything makes sound. Even if it is an empty room, there is still a good amount of sound. We went to the weight room, it was empty and I talked into the sound level meter. It read 95 decibels and I think it was from my voice and the echoing of the empty room. The gym was 69, our stomping feet in the back hall was 79, utility room 74.5, art room 73, wood tech 77.9, vending machine 64, coir singing 70, nutrition room 66, dryer 68.6, running water 73, someone talking quietly was 65, copy machine 63, spanish room 64,h room 63 and me screaming in an empty room was 86. My scream was 86 and talking was in the 70s. Too loud in the classroom in my opinion is in the 80s because that is going to be too distracting for kids to concentrate. I feel the voices would create the sound of 80 decibels and it would be much too loud for kids. I think each classroom should be the in the mid 70s because it would be easier for everyone to concentrate but it would also be a positive learning environment for everyone to participate and hear what is being said. I thought it was interesting that even an empty room had such a high amount of decibels. I thought it would be lower because there was no one talking or making extra sounds. Loudness depends on the environment and extra sounds in the environment. I really liked learning about the sounds and decibels throughout the school.

Frequency...again

We measured frequency and found the wave of sounds. The crest is the top of the wave and the trough is the bottom. We needed to zoom in on the wave so that we could have a clearer picture and discover the sound more clearly. It was hard to get a good reading every time because not every sound came out clearly and made a nice wave. Zooming in helped to see the wave and find the crest and trough more easily. You take the number of waves divided by the time and get frequency. The frequency I got for the tuning fork was 522 frequency. I got 3125 for the frequncy of the speaking voice, which is too high. I got 869.6 frequency for the singing voice. Low frequency sounds travel better. Frequency is able to be calculated but it is hard to get a good looking sound wave and to find the right frequency.

Animals and Singers: Hearing and Singing Frequencies

All animals and humans hear and can sing different frequencies, measured in Hertz. Some animals can hear higher pitches than humans. Low frequency sounds travel better.
Hearing:
Humans: 20 Hz-20,000 Hz
Dogs: 40 Hz-60,000 Hz
Bats: 20 Hz-120,000 Hz
Mice: 1 kHz-70 or 90 kHz
Cat: 100 Hz- 60,000 Hz
Elephant: 1 Hz-20,000 Hz
Rat: 1,000 Hz- 90,000 Hz
Noctuid moth: 1,000 Hz- 90,000 Hz
Grasshopper: hear up to 50,000 Hz
Dolphin: hear up to 100,000 Hz
Pigeon: hear as low as .1 Hz
Singing:
Mice: 40 kHz
Bottlenose dolphins: 0.25 kHz- 150 kHz
Harbour porpoise: 2 kHz- 110 kHz
Soprano: G3 (below middle C4) to F6, above C6 or higher
Altos: low c3 (below middle C4) to high C6 or up to high A6
Tenor: C (octave below middle C) up to a high C, D or above
Bass: low E (or lower) and octave below middle C to E, F, G or above middle C

Wordbank for Crossword

Rarefaction
Wavelength
CarrierMedium
Period
Interference
Octave
Vibration
Resonance
NervePulses
Frequency
Cycles
Pitch
Timbre
ToneQuality
Envelope
Rectangle
Partials
Reverberation
ModeShape
Sound

Across
2. Doubling or halving of a frequency
4. The same vibration will have different wavelengths depending on the_______________
6. Natural frequency associated with a particular pattern of vibration.
8. Sound waves have two phases: compression and ____________________
9. "Color" of the sound.
10. Two waves traveling in the opposite direction
11. Logitudinal mechanical pressure wave with particles traveling toward or away from the source of vibration.
12. How we perceive and interpret frequency.
13. Number of disturbances per second, measured in Hertz
15. Additional frequencies, not harmonic.
Down
1. Stream of continuing sound.
3. Distance between 2 compression or rarefaction cycles.
5. Timbre is ___________ of sound.
7. Shape of a sound.
14. The more _______per unit, the higher the frequency