Amplification and Decibels

[shaunnutley]

If a sound is amplified does this mean the volume is increased? i ask this because i notice that if i amplify a alarm clock which is 112 dB and adjust the volume on a pair of speakers to 112dB it sounds a lot louder but obviously the decibels are the same. Also, if the volume in decibels is still the same would i still NOT be able to hear someone from 50 ft away even if they were amplified in the same way as my alarm clock or would there volume sill have to be increased for me to hear them?

[mjd]

If a sound is amplified then it's amplitude is increased and it will sound louder. There is, I think, no such parameter as volume associated with sound. Perhaps you have got it from your home electrical appliacces (radio, hifi, television, mp3 player) where there is a volume control to increase the level of sound output.

Strictly speaking a meaasurement in dBs is a ratio not an absolute value so without knowing how the 112dB from your alarm clock and the 112db from your speakers were defined/measured it's impossible to say.

I don't understand the final part of your question.

[mibn2cweus]

The sound radiation pattern from your alarm clock is not likely to be duplicated by the speaker in your sound system, especially when you are comparing the alarm clocks radiation pattern to that of two separate speakers?

Sound has many properties other than decibel level that contribute to perception. Hearing is not a linier process, neither in regard to frequency nor amplitude. The human voice has a complex multifaceted sound composition. In comparison to the bleeping from an alarm clock. For a specified sound level the human voice would be generating and distributing that sound level over a wide spectrum of frequencies and would be hard pressed to faithfully duplicate the bleeping sound of the alarm clock. Sound of a specific frequency would be perceived as much louder than the same acoustic energy level spread over a wide range of frequencies, white noise (similar to the rushing sound of a waterfall) for example.

When attempting to duplicate sound levels from your sound system to that of your alarm clock you will probably achieve more satisfactory results by measuring levels within the listening area than from a very small distance from the sound radiating sources. Also home sound systems are not designed for the kind of research you are doing. Reproducing one specific frequency at high levels is not generally required for music program material. I hope you are reasonably limiting your exposure to loud, frequency specific, sounds.

I hope you find some of this helpful to answering your questions.