> I've tried generating high frequency test tones in Audacity on a PC, but=
the system doesn't seem to be able to reproduce them over about 20kHz. I d=
on't know if the limitation is the soundcard or the speakers. I've tried ea=
rphones instead of the speakers, in the hope that a small driver can go hig=
her, without much improvement, so I suspect it's the sound card.
Hi Peter,
You need to adjust the playback sample rate on the Windows Control Panel (=
Hardware and Sound > Manage Audio Devices > Playback > Properties > Advance=
d. Select here 192 kHz. The sound cards in most computers support that rate=
for playback. If it still does not work, you might just try a different co=
mputer.
You are correct about the earphones. Even the tiny internal speakers on ch=
eap laptops and tablet PC's can reproduce ultrasounds well beyond 20 kHz. T=
he sound levels that can be achieved at higher ultrasonic frequencies are h=
owever quite low. So, you probably have to put the bat detector directly in=
front of the speaker.
Regards,
Raimund
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