Low vs High Frequency Travelling Distance

[SniphzR]

An interesting (for me at least) question crossed my mind. What I experienced is if I'm on a train, and a some1 is listening music on his earphones next to me I can only hear the high frequency sounds but if there is a party in the neighbourhood the most I hear are low frequency sounds. Why is that?

[Slottr]

Probably a balance of the treble/bass. Earbuds tend to focus on trebles.

 

Correct me if wrong

[WoodenMarker]

Quote

The amount of absorption depends on the frequency of the sound. A high frequency sound has many cycles in a second, and the particles in the medium are therefore vibrating very rapidly. Just as when you rub your hands together very rapidly, this produces more heat than if you rub your hands together slowly. Since the molecules get their energy to vibrate from the sound wave, the sound wave will run out of energy sooner when it is a high frequency sound. This means that, under the same conditions, a high frequency sound won’t travel as far as a low frequency sound.

https://dosits.org/science/movement/why-does-sound-get-weaker-as-it-travels/sound-absorption/

 

When you're on a train, the low frequency sounds blend into the background more easily.

[Ahoy Hoy]

1 hour ago, SniphzR said:

An interesting (for me at least) question crossed my mind. What I experienced is if I'm on a train, and a some1 is listening music on his earphones next to me I can only hear the high frequency sounds but if there is a party in the neighbourhood the most I hear are low frequency sounds. Why is that?

3

When you're next to a guy wearing headphones they produce very little lower frequencies most of the time so you're struggling to hear them over background noise. Like said before trains pretty rubbly engine probably too much background noise.

 

 

For the party situation, a few things are probably happening.

1 low frequencies travel further because high frequencies require more energy.

2 Walls and buildings block high frequency with absorption and reflection. While the low frequencies can be so large that the wavelength is bigger then the wall or house and in simple terms go right over the wall OR the wall is just not sturdy enough and the wall just vibrates and the sound goes right through (like the floor of the upstairs apartment, floorboards not thick enough and every noise just goes right through).

[agent_x007]

 

25 minutes ago, Ahoy Hoy said:

For the party situation, a few things are probably happening.

1 low frequencies travel further because high frequencies require more energy.

2 Walls and buildings block high frequency with absorption and reflection. While the low frequencies can be so large that the wavelength is bigger then the wall or house and in simple terms go right over the wall OR the wall is just not sturdy enough and the wall just vibrates and the sound goes right through (like the floor of the upstairs apartment, floorboards not thick enough and every noise just goes right through).

It's exactly the opposite...
Ad. 1.
Subwoofers usually have more power than satelite speakers for a good reason.
Ad. 2. Bolded part : WTF ?

@SniphzR
1) "Party" sound system has MANY MORE times the power of headphones, and for bass to cover a good ammount of distance it simply needs that kind of power.
2) Headphones on your head direct sound to your ears.
You only hear high/mid frequencies because they resonate with plastic parts in headphones A LOT easier.
3) Ears and brains are tuned for mid to higher frequency sounds (legacy of hunting for animals).
It means, you may need more dB for low frequencies to actually hear them (depends greatly on persons hearing tho).

[Ahoy Hoy]

20 hours ago, agent_x007 said:

 

It's exactly the opposite...
Ad. 1.
Subwoofers usually have more power than satelite speakers for a good reason.
Ad. 2. Bolded part : WTF ?

@SniphzR
1) "Party" sound system has MANY MORE times the power of headphones, and for bass to cover a good ammount of distance it simply needs that kind of power.
2) Headphones on your head direct sound to your ears.
You only hear high/mid frequencies because they resonate with plastic parts in headphones A LOT easier.
3) Ears and brains are tuned for mid to higher frequency sounds (legacy of hunting for animals).
It means, you may need more dB for low frequencies to actually hear them (depends greatly on persons hearing tho).

6

1 Yes, it is correct. Higher frequencies require more energy to travel through the air due to the short wavelength. Subwoofers require more energy because they use large drivers so have a more friction against the air than smaller mid and high drivers.

2 I can get some links and draw you a diagram but in the basic lamens terms thats kind of correct. Its also kind of wrong but I didnt want to over complicate the explanation. The fact is depending on wall height and thickness soundwaves at certain frequencies normally lower will just go over it. A standard fence will block a lot of high and mid but hardly any low. 

 

Your points

1 No shit sherlock, The "bass" needs a higher amount of power since low frequencies drivers are normally larger 10+ inches. The good amount of distance doesn't make much sense. Volume decrease is pretty standard until you start reaching major distance. which is why my example of a fog horn works, its not designed for the first mile of noise travel its like the 4th 5th mile where the low frequency is louder than the high. There's also something to do with the waves bouncing the low frequency as well but.

 

2 Thats true but only because of the plastic casing. If the speaker driver is bigger then 1/4 of the wavelength (i think off the top of my head) it will be directive. A standard 4 inch driver in a headphone would mean everything above 5kHz is directed towards the listener everything below is produced in omnidirectional, so everyone would hear that if it wasnt for the casing.

 

3 Nop theyre not tuned for hunting animals theyre tuned for human speech. Frequencies of human speech land perfectly in line with the sensitivity of the ear. The second part of that statement is correct. We do have a poorer hearing of lower frequencies.