ANY-maze Help > The ANY-maze reference > The Protocol page > The elements of a protocol > Inputs and outputs > Speakers > Setting up a speaker > Specifying the volume of the sound

Specifying the volume of the sound

In brief

You can specify the volume of the sound played by a speaker by dragging the volume slider on the speaker's settings page.

Details

Volume is shown as a percentage scale, with 0% being silent (the speaker will actually be muted) and 100% being the maximum volume available.

The actual volume of a sound depends on a number of factors other than the volume setting. These include the volume of the source signal (for example, a sound file can be recorded with a low or high volume) and the speaker being used.

It's also important to understand that the volume of a tone played by a speaker depends on the frequency of the tone, because speakers (especially cheap ones) don't have a flat frequency response. This means, for example, that a 500Hz tone played at 80% volume may not sound as loud as a 3000Hz tone played at the same volume.

Volume in decibels

You may be wondering why ANY-maze uses a percentage as the volume scale rather than using decibels; after all, in papers, it's common for researchers to report the volume of, for example, a cue tone, in decibels, making it easy for others to replicate their conditions.

The answer is that ANY-maze simply can't know what the final volume (in decibels) will be.

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In most cases, ANY-maze is simply requesting the I/O device to play the sound and it doesn't know how loud the device will play it.

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The final volume is very dependent on the speaker used. So if ANY-maze was to play two identical tones at the same volume through two identical audio devices, the final volume would almost certainly be different if two different speakers were used.

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When playing a sound file, the volume is very dependent on the recording.

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The final volume will depend on the acoustics of the location where the sound is being played.

Of course, that doesn't help you if you want to play a 1KHz tone at 80 decibels. In this case, the answer is to use a 'Sound level meter', which will allow you to measure the volume at the location where the animal will be. So then you could install the meter and adjust the volume in ANY-maze until you get the level you want, 80dB in our example. This might occur with the volume at 93%, for example. But remember, if you change the speaker, or you alter the apparatus (which might change it's acoustics) then 93% will probably no longer equate to 80dB and you'll need to use the sound level meter again to check the volume.

Sound level meters are quite easy to find (a search of Google will almost certainly list lots of them) and not too expensive, but beware of very cheap devices - they'll probably be quite inaccurate.

ANY-maze help topic T0209