On my side when i launch the application from Finder Applications menu it does not ask for Microphone permission even if i have the entry in the Info.plist as you can see. 
at the end of the list .... may be i put the entires in the wrong order ?

<dict>

        <key>NSPrincipalClass</key>

        <string>NSApplication</string>

        <key>CFBundleDevelopmentRegion</key>

        <string>English</string>

        <key>CFBundleExecutable</key>

        <string>sdrangel</string>

        <key>CFBundleGetInfoString</key>

        <string>SDR Rx/Tx software for Airspy, Airspy HF+, BladeRF, HackRF, LimeSDR, PlutoSDR, RTL-SDR, SDRplay RSP1 and FunCube</string>

        <key>CFBundleIconFile</key>

        <string>SDRangel.icns</string>

        <key>CFBundleIdentifier</key>

        <string>com.f4exb.SDRangel</string>

        <key>CFBundleInfoDictionaryVersion</key>

        <string>6.0</string>

        <key>CFBundleLongVersionString</key>

        <string>4.14.8-2-g213d5ed82</string>

        <key>CFBundleName</key>

        <string>sdrangel</string>

        <key>CFBundlePackageType</key>

        <string>APPL</string>

        <key>CFBundleSignature</key>

        <string>????</string>

        <key>CFBundleVersion</key>

        <string>4.14.8-2-g213d5ed82</string>

        <key>NSHumanReadableCopyright</key>

        <string>Copyright (c) 2019 Edouard Griffiths. All rights reserved.</string>

        <key>ForAppStore</key>

        <string>yes</string>

        <key>LSApplicationCategoryType</key>

        <string>public.app-category.education</string>

        <key>NSHighResolutionCapable</key>

        <string>True</string>

        <key>NSSupportsAutomaticGraphicsSwitching</key>

        <true/>

        <key>NSMicrophoneUsageDescription</key>

        <string>This app requires microphone access</string>

</dict>

</plist>