Loma Prieta--Upper Mt Madonna Rd., Santa Clara County, CA, 2022-04-26
Chestnut-backed Chickadee calls. You can also hear a Red-shouldered Hawk and Acorn Woodpeckers in the background.
References:
Chestnut-backed Chickadee:
https://www.allaboutbirds.org/guide/Chestnut-backed_Chickadee/sounds
Red-shouldered Hawk:
https://www.allaboutbirds.org/guide/Red-shouldered_Hawk/sounds
Acorn Woodpecker:
https://www.allaboutbirds.org/guide/Acorn_Woodpecker/sounds
I used my android phone to record the sound and Audacity to remove clicks and background noise and to normalize the volume according to the recommendations in the following video:
https://www.youtube.com/watch?v=GYqogvHYn28
High Pass Filter: 1200 Hz
Roll-off: 48 dB
Normalize Peak Amplitude: -3 dB
"Noise Reduction" option not used