My acoustically-minded friend had the following to say:
> Off the top of my head, I'm guessing the problem has mostly to do with background noise, and it only working in moderately quiet environments.
> As for locating the source of a sound, there's plenty of research that's been done about that. A directional mic doing sweeps is probably not your best bet, as it would be slow and difficult to cover three dimensions. I would think using an array of microphones and using volume and time delay to identify location would be much easier. Setting them up in a triangular pyramid would, I think, allow you to triangulate a sound's position in three dimensions. The problem with this two-fold: it's still not super precise, and the mosquito's whine is a steady sound, not an impulse where it's easy to identify time-delay between locations. You'd probably need to have an incredibly high sample rate to identify strong enough variations in the sound of a mosquito to effectively use time-delay, or place them far enough apart to rely on relative volume. Maybe a set of microphones you can set up around a room, rather than a single location would work better.
> I think this could be solvable by having the laser aim towards the sound and do a rapid sweep of the area, rather than a precision strike. You could also potentially have the device hit targets that will confirm they are being hit when you are setting it up so it can calibrate to the environment that it's in under regular conditions.
> Another thing to consider is that you would also probably need temperature and humidity detection, as both of those can affect how sound travels, even over short distances.
I then did more research on the killing part of this—the laser. The product I linked above uses two lasers—a low-power one to pinpoint the target and to "listen" for its exact frequency to rule out benign insects and a high-power one to give it instant heatstroke or burn off its wings. But with computer-aimed lasers (even non-burning visible green lasers), accidental blindness is a real concern especially indoors where the beam can unexpectedly reflect off glass or other shiny things. So maybe a narrow, powerful non-coherent flashlight could act as a spotlight and that'd be good enough for a human to still kill it.
All this work, to suggest a fly spotlight device is hysterical. That would be marginally helpful, and maximally frustrating. I lend the project my full support were it to ever materialize.
> Off the top of my head, I'm guessing the problem has mostly to do with background noise, and it only working in moderately quiet environments.
> As for locating the source of a sound, there's plenty of research that's been done about that. A directional mic doing sweeps is probably not your best bet, as it would be slow and difficult to cover three dimensions. I would think using an array of microphones and using volume and time delay to identify location would be much easier. Setting them up in a triangular pyramid would, I think, allow you to triangulate a sound's position in three dimensions. The problem with this two-fold: it's still not super precise, and the mosquito's whine is a steady sound, not an impulse where it's easy to identify time-delay between locations. You'd probably need to have an incredibly high sample rate to identify strong enough variations in the sound of a mosquito to effectively use time-delay, or place them far enough apart to rely on relative volume. Maybe a set of microphones you can set up around a room, rather than a single location would work better.
> I think this could be solvable by having the laser aim towards the sound and do a rapid sweep of the area, rather than a precision strike. You could also potentially have the device hit targets that will confirm they are being hit when you are setting it up so it can calibrate to the environment that it's in under regular conditions.
> Another thing to consider is that you would also probably need temperature and humidity detection, as both of those can affect how sound travels, even over short distances.
I then did more research on the killing part of this—the laser. The product I linked above uses two lasers—a low-power one to pinpoint the target and to "listen" for its exact frequency to rule out benign insects and a high-power one to give it instant heatstroke or burn off its wings. But with computer-aimed lasers (even non-burning visible green lasers), accidental blindness is a real concern especially indoors where the beam can unexpectedly reflect off glass or other shiny things. So maybe a narrow, powerful non-coherent flashlight could act as a spotlight and that'd be good enough for a human to still kill it.