Volume is how many decibels?

With so many new studies coming out saying that music should be kept at a certain level (usually described in terms of decibels), how can we measure the decibel level on a device (ipod, laptop, etc.). In other words, what does the volume level mean in terms of decibels? Does a volume of 30 on the vista sound icon mean 15 db... etc.?

Also, external speakers normally have to be cranked higher, while headphones get the same level of noise from a lower setting.

 

Wow I wish I new more so I could help more. But here goes. You can not ever have a volume setting correspond to a db level. Reason is other variables come into play. Environment, open or closed. Closed will limit dissipation of the sound, open would disperse more efficiently. Also the same source would likely be lower db for me than you if I was further away unless some kind of acoustic anomaly.

Also be aware 5db is not half 10db as it is a scale of magnitude I think?

Pay attention to w or mw as those are the measures of the device's output and more useful for comparative purposes. And I might ad more likely to give you the measurement you seek.

So much more hearing loss because of IPod's only because headphones are increasing the hearing loss.

 

You also have to realize that the impedance of different headphones are different, meaning that they take different ammounts of power to push the drivers. Some headphones would completely blast your ears out at half volume of my computer, others I've had to turn it all the way up. Biggest thing is to keep the levels realistic, and don't try to drown out other sounds with your music, use isolation or noise canceling for that.

 

Decibels is a measure of sound level intensity and is based on a logarithmic scale. Every 3dB corresponds to a doubling in sound intensity (ie. 43 dB is 2x as intense as 40dB). The thing with decibels is it's measured relative to a reference level. Plotting your hearing, the x-axis is the frequency of the sound and the y-axis is sound intensity. Your hearing is more sensitive at certain frequencies, hence we use a weighting system for sound levels (ie. A-weighting at 1000Hz is at 0dB, while 100Hz is at -20dB, which means you hear the same intensity of a sound at 100Hz at 30dB as with a sound at 1000Hz at 50dB). Sorry if this confuses you, sounds are very complex and unfortunately because of this companies are not held to any specific standards in terms of labelling sounds on their products.