# How to keep the same power (sonority) between pure sines?

I have a list of sine waves in 1/3 Octave (63,80,100...1k,1.25k,etc) that I want to reproduce with the same power. Right now I just have a global gain that applies to all this freqs, but of course the high frequencies are louder that the lower ones.

I am not sure how to keep the same power between them, I suppose I can use the principle of the pink noise and convert the gain (normalized 0-1) to dB, lower 3dB per octave as I go up in the list and go gack to normalized. But I am not sure if this is the correct way to achieve what I need.

How can I Keep the same power/Sonority?

Edit: By equal power I mean they sound with "the same volume" to person listen to them.

For info, the user will be using mostly headphones. This is running on mobile phones.

• Please be clear: By the same power, do you mean electrical voltage/current at the amplifer input or the acoustic pressure wave power at the output of the loudspeaker, or the percepted power of the sensation in the human hearing system? – Fat32 Dec 26 '17 at 21:05
• You should consider that of two tones exactly equal in power, the one at the higher frequency (up to like 3 kHz?) will sound louder to the human ear. Look up "equal loudness contours" to see this concept visualized. – goldrik Dec 27 '17 at 9:16
• @Fat32 I was not sure how to translate this, in spanish it is "Sonoridad". I used "power" just because it is what Wikipedia uses when explaining about the characteristics of the Pink Noise. I added an edit. It is about the percepted power. – distante Dec 27 '17 at 12:15
• @goldrik I now the Fletcher Munson curves but I do not know how to apply it here because the work with SPL and I Do not have direct control with that. – distante Dec 27 '17 at 12:15