Analysis of the Acoustic Propagation Parameters of the Natural Sounds of Delphinapterus Leucas and Odorrana Tormota Fundamental in the Startle of the Female Anopheles Gambiae

The female Anopheles gambiae, a malaria vector detects ultrasound by the antennae causing startle responses attributed to neural stress. Resistance to the control and treatment measures by malaria vectors and pathogens has resulted to a low decline rate in malaria cases and deaths. Studies have shown a 46% evasive response in the A. gambiae by the 35-60 kHz sounds of Odorrana tormota. This study determined, analysed and compared acoustic propagation parameters of the sounds of Delphinapterus leucas and Odorrana tormota fundamental in the startle of the mosquito. The sound of D. leucas and O. tormota were acquired. The Avisoft-SASLab 5.2 and Raven Pro 1.5 software were used in the study. Spectral analysis of sounds of D. leucas and O. tormota showed composition of pulsate audible and utrasonic harmonics, FM and CF modulation. The mean of the fundamental frequency (mean entire) of D. leucas was 1.684kHz, less by 3.712kHz from that of the sound of O. tormota differing insignificantly. The sound of D. leucas recorded a maximum value of 64.8kHz in maximum frequency (mean) which was 25.5kHz above that of O. tormota with a highly significant difference. Also, the sound of D. leucas had a 64.10kHz bandwidth (mean entire) wider than that of O. tormota by 53.64kHz, a highly significant difference. The peak amplitude (mean entire) of the sound of D. leucas was 89.05Pa less by 39.837kHz from that of the sound of O. tormota differing significantly. The mean acoustic energy of D. leucas was 0.07Pa2s whereas the O. tormota possessed 2,496.63Pa2s differ insignificantly. These parameters are essential in the study of mosquito repellence and design of a repellent device.