High pitched cat deterrant - will Bella notice it?

[HelloBella]

My neighbour was just chatting to me about the trouble he's been having with a local cat leaving surprises for him in his veggie patch. He told me he has installed three (THREE!) of those high pitch emitting cat deterrants. Of course these are silent to human ears, but anybody tell me if these are likely to upset my tort Bella? My guess is not, because am I right in understanding they're tuned into low pitches?

 

[HelloBella]

I know Bella likes low pitches, she knows when the hoover's going in another room and comes creeping through to sit by the warm vent!

 

[WithLisa]

I don't think she can hear it.

 

[Tidgy's Dad]

Human beings hear sounds between frequencies of 20Hz to 20 kHz; above this is ultrasonic.
Dogs and cats can hear up to at least 27 kHz so the signal would be between these two figures.
Tortoises seem to not hear terribly well at all, but can hear some sounds below our hearing range - infrasonics.
Aldabran tortoises, for example, have been measured emitting squeaks at between 0.26 to 0 80 kHz, just within our maximum range, but other tests suggest a hearing range for tortoises of as low as 50 Hz to 1500 Hz.
In short it is very unlikely your tortoise should be bothered by this alarm, it is too high a frequency sound for it to hear.

 

[Lyn W]

Hi I don't know if a tortoise can hear the sound but they do work. My neighbour's cats were always using my garden as a giant litter tray because their owner's garden is completely paved but they wouldn't bury it!, So I bought a sonic cat deterrent and hey presto no more cat pooh since! Brilliant