2007-11-29 21:21:06 · 15 answers · asked by Anonymous in Consumer Electronics ➔ Other - Electronics
Decibels (dB) are always based on a ratio -- 10 * log10(S/R), where S is the sample value, R is the reference value. So there's usually some indication of what it is you're referencing. The standard for audio is dB(SPL), where SPL is Sound Pressure Level. Other measures are for dBW (references against 1 Watt), dBV (referenced against one volt), etc.
So in the dB(SPL) measure, the reference point, 0dB, is at what's considered the threshold of human hearing (specifically a 2kHz sound is used as the reference). Think of 0dB as the loudest sound you can't actually hear, or the quietest one you possibly can.
While dB is based on a logarithmic scale, so is your hearing.. so a +4dB sound is really, really quiet. What does it sound like? Well, pretty much, something that's so quiet, you're not quite sure you're hearing anything. The sound of leaves rustling in the forest as you walk though it would probably come in around +10dB. Or quiet breathing. So maybe someone really trying hard not to make any sound would be around 4dB.
A whisper is around 15-20dB. Normal conversational talking is around 40-60dB. A jackhammer a few feet away is 100dB. "The Raconteurs" on stage from about 30ft away is 110-120dB.
2007-11-29 21:41:49 · answer #1 · answered by Hazydave 6 · 4⤊ 0⤋
4 Decibels
2016-12-14 11:16:53 · answer #2 · answered by dysart 4 · 0⤊ 1⤋
Imagine being sat in an empty field, on a totally calm night, with no traffic noise, no aircraft noise - in fact no external sound at all.
All you can hear is the blood moving through the veins in your own head. That's about 4 decibels.
2007-11-30 00:48:40 · answer #3 · answered by Nightworks 7 · 0⤊ 0⤋
If you drop a penny onto a wooden surface from a height of 5.6cm that makes a sound around 4dB
2007-11-29 21:24:03 · answer #4 · answered by Anonymous · 0⤊ 1⤋
If you mean 4dB sound pressure level, you can't hear it. If you mean a 4 dB increase in an already audible sound it is a fairly substantial increase in volume.
2007-11-29 21:24:48 · answer #5 · answered by Anonymous · 7⤊ 0⤋
1 more than 3 and 1 less than 5.
2007-11-29 21:29:45 · answer #6 · answered by Hammer&Drill 3 · 0⤊ 4⤋
A bit quieter than a mouse.
2007-11-29 21:52:40 · answer #7 · answered by Anonymous · 1⤊ 0⤋
Just over twice as loud as 0dB.
2007-11-29 21:23:49 · answer #8 · answered by Anonymous · 2⤊ 0⤋
you can't hear it. and you won't get in trouble with neighbours if you throw a party which is that "loud".
2007-11-29 21:32:47 · answer #9 · answered by Kipras 2 · 2⤊ 0⤋
thats
4 X Deci (i.e. 10) Bells ringing togather
Which equals 40 bells at once.
But I have no idea how big the bells are? :)
2007-11-29 21:24:31 · answer #10 · answered by strange_raga 4 · 0⤊ 4⤋