Apparently some drones have a problem with resonance so if you conduct an experiment of sound on them you could cause them to crash.
Components inside drones are susceptible to certain pitches .
Researchers at the Korea Advanced Institute of Science and Technology (KAIST) in Daejon, South Korea, analysed the effects of resonance on a crucial component of a drone, its gyroscope.
A gyroscope keeps a drone balanced, providing information on its tilt, orientation and rotation, allowing for micro-adjustments that keep it aloft. Hobbyist and some commercial drones use inexpensive gyroscopes that are designed as integrated circuit packages.
Gyroscopes have been designed to have resonant frequencies that are above the audible spectrum, said Yongdae Kim, a professor in KAIST’s electrical engineering department. But others are still in the audible spectrum, making them vulnerable to interference from intentional sound noise.
Matching the resonant frequency of a gyroscope causes it to generate erroneous outputs, which have an effect on its flight, Kim said.
Researchers attached to a drone a small, consumer-grade speaker that was wirelessly connected to a nearby laptop.
The drone takes off normally, but when the right noise is played through the speaker, it smacks into the ground.
“When the gyroscope starts fluctuating, it affects the rotor speed directly,” Kim said.
At 140 decibels, it would be possible to affect a vulnerable drone up from around 40 metres away, Kim said.
There are a variety of sound-related offensive and defensive devices already on the market. For example, the LRAD Corporation makes the 450XL, which it terms an “acoustic hailing device.”
It can be mounted on a vehicle or a tripod and can project a voice message up to 1,700 meters so would be a good way of delivering an attack on a drone at close quarters.