Mosquito Wing Beat Frequency

The Mosquito is a focus of much of the research that is funded by the largest philanthropic organization in the world (the Bill & Melinda Gates Foundation). The mosquito is the main vector for the malaria epidemic that we face in much of the world today. A study of the mosquito physiology may provide unitque tools to assault this highly successful organism's proliferation.

This example data is provided by Lauren Cator of the Harrington Lab at Cornell Univ. It is a low amplitude recording of the wing sound of a male mosquito. This will illustrate the use of multiple filters and a display of frequency harmonic content of a noisy signal.

Raw Data Files

• male.wav - A small microphone recording of a tethered male mosquito
• male-filtered-amped.wav - The same signal band pass filtered and amplified

This signal starts out as a noisy and can be filtered to reveal the main frequncy components of interest in the mosquito wing beat. Since we know the frequency of beat is between 600 and 1000Hz, we apply the 500Hz high-pass filter and the 1000Hz low-pass filter to reduce noise sources. The resulting signal indicates harmonics. As the mosquito stabilizes its wing beating at about 30 seconds into the recording, the main component of the wing beat frequency becomes visible (approximately 600Hz in the figure). Two harmonics of the signal are also visible in this mode.

1. Load male.wav into the analysis window
2. From the analysis menu, activate the 500Hz high-pass and 1000Hz low-pass filters
3. set the window width to 0.1s and the threshold value to 0.0011V and hit calculate
4. Low and high frequency noise is rejected and the frequency of the wing beat is displayed with harmonics