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I come across such descriptions as below when I read about

  1. "90 dB SPL with 1 watt, measured at 1 meter distance" or "Sound pressure level of 90 dB 1 W/1 m".

Another example is:

  1. "Reference test gain (60 dB SPL input)"

How can these be explained in a more clear way? In 1 they mention distance and power but in 2 they just say "60 dB SPL" input. What is meant by "60 dB input SPL"?

Transistor
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pnatk
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  • "dB SPL" is really easy to search for, and there's a wikipedia article about sound pressure that you'll find when you do that. We're not an encyclopedia, copied out on demand! Please make sure your question is well-researched :) – Marcus Müller Nov 07 '20 at 19:14
  • I know what dB SPL is but what does "60 dB input SPL" mean without a reference. That's why I asked here. – pnatk Nov 07 '20 at 19:15
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    ... read the wikipedia article. It tells you what the usual reference is. You just have to read the next five sentences after the formula. – Marcus Müller Nov 07 '20 at 19:16
  • @pnatk you ask a question then quote yourself incorrectly in a comment. Like MM says you need to do research if it's not immediately obvious. Then, make proper quotes in your question and cite the source what you read that confuses you. Added context from the sources would have served you well. – Andy aka Nov 07 '20 at 19:25

1 Answers1

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  1. The usual way to tell how much a speaker makes acoustic sound pressure with 1W electric input power at 1m distance in front of the speaker. The signal should be pink noise limited to the intended frequency band of the speaker. The result presents the sensitivity of the speaker. The speaker contains the cabinet, speaker elements and possible filters, but no amps.

  2. characterizes as a single dB-number the gain of a hearing aid device in standard ANSI S3.22. The definition is complex because it takes into the account level compression in the device. Better to read the whole story here: http://www.frye.com/wp/wp-content/uploads/2013/08/ANSI09_workbook.pdf

No watts nor meters are needed because here the gain is how many more decibels sound pressure a device causes when the levels at the mic of the device and the outputted level to user's ear are compared.

The mentioned 60dB SPL is outputted to the mic of the device when the gain knob of the hearing aid device is adjusted for certain output SPL in the beginning of the measurement of the "Reference test gain" of the device.