Millisecond Forums

Determining maximum volume

https://forums.millisecond.com/Topic12924.aspx

By guycog - 4/5/2014

Hi,
I'm trying to use the Competitive Reaction Time Task and I want to limit the maximum volume the participants will hear in their headphones.
I can see where to change the relative volume (between 0 and -10000) but is there a way to know how much dB (Decibels) each level represents?

Thanks you very much,

Guy
By Dave - 4/5/2014

> [...] is there a way to know how much dB (Decibels) each level represents?
No [1]. Suppose you leave the volume unadjusted (no attenuation, i.e. -10000):

- If a system's audio amplifier is cranked to the max, the sound pressure output will be greater than when its set to half etc.
- Different WAVs may have different volume, regardless of hardware and software audio settings, a sound with a low amplitude waveform will produce less sound pressure than a sound with a more extreme waveform.

If you want to really know the dB SPL output on a given system for a given sound, you need to measure it using a suitable device, i.e. a sound level meter.

[1] I assume when your say "how much dB each level represents" what you are really asking about is *sound pressure level measured in dB* (cf. https://en.wikipedia.org/wiki/Sound_pressure#Sound_pressure_level). dB in and of itself is an abstract unit expressing a ratio on a logarithmic scale (cf. https://en.wikipedia.org/wiki/Decibel, particularly see https://en.wikipedia.org/wiki/Decibel#Uses; you seem to be mixing up or conflating dB use / meaning in acoustics vs. use / meaning in electronics).