Sound Detector Feasibility?

Hi all,

I have an idea for a project involving a music visualizer. My problem is with the sound detector - I basically want the detector to be able to reasonably detect sounds in the 100-120dB range (like music at a concert). I was originally thinking of suing the Sparkfun Sound Detector, but after looking at this page I don't think that's feasible. It looks like the highest dB gain you can reasonably get on that detector is 60dB. Would it still be able to work at the 100-120dB range though, or would there be lots of noise? And if that wouldn't work, does anyone know of any similar sound detectors that could work effectively in the 100-120dB range, and are arduino-compatible?

Thanks!

if it's too sensitive, put a sock on it. muffle the sound coming in, it effectively becomes less sensitive

holder12:
Hi all,

I have an idea for a project involving a music visualizer. My problem is with the sound detector - I basically want the detector to be able to reasonably detect sounds in the 100-120dB range (like music at a concert). I was originally thinking of suing the Sparkfun Sound Detector, but after looking at this page I don't think that's feasible. It looks like the highest dB gain you can reasonably get on that detector is 60dB. Would it still be able to work at the 100-120dB range though, or would there be lots of noise? And if that wouldn't work, does anyone know of any similar sound detectors that could work effectively in the 100-120dB range, and are arduino-compatible?

Thanks!

Why in the world would you want to take a 100-120db sound and amplify it 60db more?

Paul

An otherwise unamplified electret microphone would work to detect 100-120 dB SPL sound, using the Arduino analog input.

Typical microphone sensitivity is -44 dBV/Pa.

Normal speech is about -5 dBPa measured a certain distance from the mouth, but will vary with speaker. The threshold of pain is ~120 dB SPL (0 dBPa = 94 dB SPL).

So, the microphone output might be about -49 dBV (3.5 mV) for normal speech (close to the mouth) or -13 dBV (125 mV) for painfully loud sounds.

Cobble such a setup together and experiment.

I think you're confusing two different things, but decibels are easily confused. A decibel (dB) is, by itself, a unitless scale and has absolute meaning only in it's relationship to a reference value.

In the context of sound pressure level, such as the level of music at a concert it is referenced to the nominal threshold of human hearing (0 dB). This is more properly referred to as dB_SPL.

In the context of an active microphone it is the amplifier voltage gain following the output of the microphone element.

To design your system one takes the environment sound pressure level, determines the output voltage level of the microphone to that SPL, and then the gain of the amplifier following the microphone element will give a corresponding voltage output that one wants to be compatible with the ADC input range. Per the numbers in Post #3, you may need little or no gain after the microphone element.