4 ms·
Wouldn't it be simpler to add noise above 20kHz and ignore the key phrase if the noise is present?
by davidmurdoch 2y ago
Wouldn't it be simpler to add noise above 20kHz and ignore the key phrase if the noise is present?
- sgc 2y agoThat was my thought as well. Just use some form of acoustical fingerprinting. It would be very simple to do, and would be both robust and flexible.
- lazide 2y agoEven simpler is subtract any sound (and associated echoes) output through the speaker from any input received from the microphone.
- colanderman 2y agoEcho cancellation is much more complex than tone squelching, which is simple enough to be implemented in the analog domain.
- brazzy 2y agoEcho cancellation was implemented in the analog domain 50 years ago at the least. It's wild to see someone assume this kind of thing requires machine learning algorithms.
- lazide 2y agoI'm guessing they were (rightfully) pointing out it's still harder than just ignoring any input if there is a given tone. Which yeah, it is. I'm assuming they'd prefer to use that for things like advertisements though, since the cancellation approach lets them ‘listen’ while still talking/playing music/etc.
- xx-bean-xx 2y agono, because that 20+khz noise would be lost in any 44khz signal processing. you would have to guarantee the audio player is capable of higher bitrates
- davidmurdoch 2y agoAh, I didn't think about that. Thanks for pointing that out. Typical mics sample at 48khz, but that wouldn't leave much head room. Echo devices have an array of mics, IIRC, so I wonder if they can effectively sample at a higher rate?
- astrange 2y agoIt also isn't resilient to room echo/reflections, or EQ if people hook it up to their own speaker systems. If you listen to the Apple keynote, anytime someone says Siri the audio has been very audibly lowpassed, presumably that's enough.