Q: I'm trying to block background noise on Zoom calls with students ages 5 to 8 who are at home or in daycare. The students have noise-canceling headphones that block the noise for them, but I have to listen to the sounds of other children, siblings, parents and barking dogs.

The students use iPads that have a plug for their headphones but no plug for a noise-canceling external microphone (headphones that include microphones are expensive.) What can I do?

Sarah Renner, Minneapolis

A: You can block background racket by using noise-canceling software instead of noise-canceling microphones.

There are two types of this software: The Zoom video call app, which has controls for canceling out background noise at the student's end of the conversation. And third-party programs for your computer that cancel out student background noise before the sound plays through your computer's speaker.

In order to use the Zoom noise-canceling feature, your students must connect to the call via the Zoom app on their iPads (as opposed to connecting without the app through the Zoom website.)

In addition, an adult must examine the app's settings to make sure they aren't set to "original sound," which means background noise is not filtered out. Toggling off "original sound" automatically turns on background noise cancellation. (For directions, see tinyurl.com/y58k8f39). Unfortunately, the noise-cancellation feature in the iPad Zoom app has its limits. Unlike the computer app, the iPad app doesn't let you adjust to block specific types of sounds. It also doesn't allow noise cancellation to be increased or decreased.

A better solution may be to download a third-party noise-cancellation program to the PC or Mac that you use for Zoom sessions. The app most suited to your needs is probably "Krisp," which can filter out student background noise before you hear it. Krisp is free to use for up to 120 minutes a week; unlimited use costs $5 a month. (See details at tinyurl.com/y5wcz5vt and downloads at tinyurl.com/yy95tk8s).

Q: I copied some photos taken with a camera to my PC, and from there to my iPhone 6s. The photos are on the phone in a folder called "From My Mac," which is odd because I've never owned a Mac. Now I'd like to delete those photos, but the phone can't do it. I also tried erasing them via my PC (with and without iTunes), but it can't even "see" those photos on the phone. What can I do?

Mark Stedman, Afton, Minn.

A: The "From My Mac" folder stores pictures that were copied to the iPhone from any computer. This folder is part of the iPhone's Photos app, just like the "Camera Roll" folder that stores pictures taken with the phone. But, due to a quirk in the iPhone's software, the phone can easily erase the photos in the "Camera Roll," but not those in the "From My Mac" folder.

There are two solutions: You can delete all the "From My Mac" photos by disabling, then re-enabling, "iCloud Photos" and in the resulting menu choosing "remove photos" (see "method 1" at tinyurl.com/y6xkqhal). To delete some but not all the photos, try computer apps "CopyTrans Photo" ($20, see tinyurl.com/y76refj9) or "DearMob iPhone Manager" ($30-a-year, see tinyurl.com/y23bsnyw).

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