Sounds found in and extracted from System/Library/Audio/UISounds in multiple formats. I only discovered these because of this Siri Shortcut.
{
"Phone 0":"file:///System/Library/Audio/UISounds/nano/dtmf-0.caf",
"Phone 1":"file:///System/Library/Audio/UISounds/nano/dtmf-1.caf",
"Phone 2":"file:///System/Library/Audio/UISounds/nano/dtmf-2.caf",
"Phone 3":"file:///System/Library/Audio/UISounds/nano/dtmf-3.caf",
"Phone 4":"file:///System/Library/Audio/UISounds/nano/dtmf-4.caf",
"Phone 5":"file:///System/Library/Audio/UISounds/nano/dtmf-5.caf",
"Phone 6":"file:///System/Library/Audio/UISounds/nano/dtmf-6.caf",
"Phone 7":"file:///System/Library/Audio/UISounds/nano/dtmf-7.caf",
"Phone 8":"file:///System/Library/Audio/UISounds/nano/dtmf-8.caf",
"Phone 9":"file:///System/Library/Audio/UISounds/nano/dtmf-9.caf",
"Phone S":"file:///System/Library/Audio/UISounds/nano/dtmf-star.caf",
"Phone H":"file:///System/Library/Audio/UISounds/nano/dtmf-pound.caf",
"Phone Busy A":"file:///System/Library/Audio/UISounds/nano/busy_tone_ansi.caf",
"Phone Busy B":"file:///System/Library/Audio/UISounds/ct-busy.caf",
"Phone Busy C":"file:///System/Library/Audio/UISounds/nano/busy_tone_cept.caf",
"Phone Congestion":"file:///System/Library/Audio/UISounds/ct-congestion.caf",
"Phone Tone UK":"file:///System/Library/Audio/UISounds/nano/ringback_tone_uk.caf",
"Phone Tone A US":"file:///System/Library/Audio/UISounds/nano/ringback_tone_aus.caf",
"Phone Tone HK":"file:///System/Library/Audio/UISounds/nano/ringback_tone_hk.caf",
"Phone Tone A":"file:///System/Library/Audio/UISounds/nano/ringback_tone_ansi.caf",
"Phone Tone C":"file:///System/Library/Audio/UISounds/nano/ringback_tone_cept.caf",
"Phone Waiting A":"file:///System/Library/Audio/UISounds/nano/call_waiting_tone_ansi.caf",
"Phone Waiting B":"file:///System/Library/Audio/UISounds/nano/ct-call-waiting.caf",
"Phone Waiting C":"file:///System/Library/Audio/UISounds/nano/call_waiting_tone_cept.caf",
"Phone Error":"file:///System/Library/Audio/UISounds/ct-error.caf",
"Phone Stop":"file:///System/Library/Audio/UISounds/nano/end_call_tone_cept.caf",
"Video Call Tone":"file:///System/Library/Audio/UISounds/nano/vc~ringing.caf",
"Video Call Tone Watch":"file:///System/Library/Audio/UISounds/nano/vc~ringing_watch.caf",
"Video Call Invite":"file:///System/Library/Audio/UISounds/nano/vc~invitation-accepted.caf",
"Video Call Multi Invite":"file:///System/Library/Audio/UISounds/nano/MultiwayInvitation.caf",
"Video Call Multi Start":"file:///System/Library/Audio/UISounds/nano/MultiwayJoin.caf",
"Video Call Multi End":"file:///System/Library/Audio/UISounds/nano/MultiwayLeave.caf",
"Video Call End":"file:///System/Library/Audio/UISounds/nano/vc~ended.caf",
"Camera Start":"file:///System/Library/Audio/UISounds/begin_record.caf",
"Camera Stop":"file:///System/Library/Audio/UISounds/end_record.caf",
"Camera Countdown Start":"file:///System/Library/Audio/UISounds/camera_timer_countdown.caf",
"Camera Countdown Stop":"file:///System/Library/Audio/UISounds/camera_timer_final_second.caf",
"Camera Shutter":"file:///System/Library/Audio/UISounds/photoShutter.caf",
"Camera Burst Start":"file:///System/Library/Audio/UISounds/Modern/camera_shutter_burst_begin.caf",
"Camera Burst Middle":"file:///System/Library/Audio/UISounds/Modern/camera_shutter_burst.caf",
"Camera Burst End":"file:///System/Library/Audio/UISounds/Modern/camera_shutter_burst_end.caf",
"Photo Memory":"file:///System/Library/PrivateFrameworks/ToneLibrary.framework/AlertTones/PhotosMemoriesNotification.caf", "Photo Sharing":"file:///System/Library/PrivateFrameworks/ToneLibrary.framework/AlertTones/PhotosSharingPostTone.caf",
"Health":"file:///System/Library/Audio/UISounds/nano/Alert_Health_Haptic.caf",
"Activity Behind":"file:///System/Library/Audio/UISounds/nano/Alert_ActivityGoalBehind_Haptic.caf",
"Activity Friend":"file:///System/Library/Audio/UISounds/nano/Alert_ActivityFriendsGoalAttained_Haptic.caf",
"Activity Goal":"file:///System/Library/Audio/UISounds/nano/Alert_ActivityGoalAttained_Haptic.caf",
"Workout Auto":"file:///System/Library/Audio/UISounds/nano/WorkoutCompleteAutodetect.caf",
"Workout Start":"file:///System/Library/Audio/UISounds/nano/WorkoutStartAutodetect.caf",
"Workout Countdown":"file:///System/Library/Audio/UISounds/nano/WorkoutCountdown_Haptic.caf",
"Workout Pace Above":"file:///System/Library/Audio/UISounds/nano/WorkoutPaceAbove.caf",
"Workout Pace Below":"file:///System/Library/Audio/UISounds/nano/WorkoutPaceBelow.caf",
"Workout Complete":"file:///System/Library/Audio/UISounds/nano/WorkoutComplete_Haptic.caf",
"Workout Saved":"file:///System/Library/Audio/UISounds/nano/WorkoutSaved_Haptic.caf",
"Audio Passcode Tone":"file:///System/Library/PrivateFrameworks/AudioPasscode.framework/WOCAudioPasscodeTone.wav",
"Sw Test":"file:///System/Library/Audio/UISounds/nano/SwTest1_Haptic.caf",
"Lock":"file:///System/Library/Audio/UISounds/lock.caf",
"Unlock":"file:///System/Library/Audio/UISounds/nano/AutoUnlock_Haptic.caf",
"Passcode Unlock":"file:///System/Library/Audio/UISounds/nano/OnOffPasscodeUnlock_Haptic.caf",
"Battery Low":"file:///System/Library/Audio/UISounds/nano/Alert_BatteryLow_10p_Haptic.caf",
"Low Power":"file:///System/Library/Audio/UISounds/low_power.caf",
"Connect Power":"file:///System/Library/Audio/UISounds/connect_power.caf",
"Air Power":"file:///System/Library/Audio/UISounds/engage_power.caf",
"Air Power Short":"file:///System/Library/Audio/UISounds/engage_power_short.caf",
"Focus Icon":"file:///System/Library/Audio/UISounds/focus_change_app_icon.caf",
"Focus Keyboard":"file:///System/Library/Audio/UISounds/focus_change_keyboard.caf",
"Focus Large":"file:///System/Library/Audio/UISounds/focus_change_large.caf",
"Focus Small":"file:///System/Library/Audio/UISounds/focus_change_small.caf",
"Focus Ringer":"file:///System/Library/Audio/UISounds/RingerChanged.caf",
"Dictate Start":"file:///System/Library/Audio/UISounds/jbl_begin.caf",
"Dictate Cancel":"file:///System/Library/Audio/UISounds/jbl_cancel.caf",
"Dictate Ambiguous":"file:///System/Library/Audio/UISounds/jbl_ambiguous.caf",
"Dictate No Match":"file:///System/Library/Audio/UISounds/jbl_no_match.caf",
"Dictate Confirm":"file:///System/Library/Audio/UISounds/jbl_confirm.caf",
"Key Click":"file:///System/Library/Audio/UISounds/key_press_click.caf",
"Key Delete":"file:///System/Library/Audio/UISounds/key_press_delete.caf",
"Key Modifier":"file:///System/Library/Audio/UISounds/key_press_modifier.caf",
"Key Clear":"file:///System/Library/Audio/UISounds/keyboard_press_clear.caf",
"Key Delete 2":"file:///System/Library/Audio/UISounds/keyboard_press_delete.caf",
"Key Normal":"file:///System/Library/Audio/UISounds/keyboard_press_normal.caf",
"Wheels Of Time":"file:///System/Library/Audio/UISounds/wheels_of_time.caf",
"Alarm Haptic":"file:///System/Library/Audio/UISounds/nano/Alarm_Haptic.caf",
"Alert":"file:///System/Library/Audio/UISounds/nano/Alert_3rdParty_Haptic.caf",
"Beep":"file:///System/Library/Audio/UISounds/SIMToolkitGeneralBeep.caf",
"Begin":"file:///System/Library/Audio/UISounds/nano/ET_BeginNotification_Haptic.caf",
"Critical":"file:///System/Library/Audio/UISounds/3rd_party_critical.caf",
"DND":"file:///System/Library/Audio/UISounds/nano/DoNotDisturb_Haptic.caf",
"Dropped":"file:///System/Library/Audio/UISounds/SIMToolkitCallDropped.caf",
"Hourly Chime":"file:///System/Library/Audio/UISounds/nano/HourlyChime_Haptic.caf",
"Hummingbird Starting up":"file:///System/Library/Audio/UISounds/nano/SystemStartup_Haptic.caf",
"Hummingbird Notification":"file:///System/Library/Audio/UISounds/nano/HummingbirdNotification_Haptic.caf",
"Hummingbird Completion":"file:///System/Library/Audio/UISounds/nano/HummingbirdCompletion_Haptic.caf",
"Key Tone":"file:///System/Library/Audio/UISounds/ct-keytone2.caf",
"Navigation Pop":"file:///System/Library/Audio/UISounds/navigation_pop.caf",
"Navigation Push":"file:///System/Library/Audio/UISounds/navigation_push.caf",
"Navigation Move":"file:///System/Library/Audio/UISounds/nano/NavigationGenericManeuver_Haptic.caf",
"Navigation Left":"file:///System/Library/Audio/UISounds/nano/NavigationLeftTurn_Haptic.caf",
"Navigation Right":"file:///System/Library/Audio/UISounds/nano/NavigationRightTurn_Haptic.caf",
"Directions In":"file:///System/Library/Audio/UISounds/nano/Alert_MapsDirectionsInApp_Haptic.caf",
"Direction Up":"file:///System/Library/Audio/UISounds/nano/3rdParty_DirectionDown_Haptic.caf",
"Direction Down":"file:///System/Library/Audio/UISounds/nano/3rdParty_DirectionUp_Haptic.caf",
"NACK":"file:///System/Library/Audio/UISounds/SIMToolkitNegativeACK.caf",
"PACK":"file:///System/Library/Audio/UISounds/SIMToolkitPositiveACK.caf",
"Scan Complete":"file:///System/Library/Audio/UISounds/access_scan_complete.caf",
"Shake":"file:///System/Library/Audio/UISounds/shake.caf",
"Short Double High":"file:///System/Library/Audio/UISounds/short_double_high.caf",
"Short Double Low":"file:///System/Library/Audio/UISounds/short_double_low.caf",
"Short Double Low 9":"file:///System/Library/Audio/UISounds/middle_9_short_double_low.caf",
"Short Low High":"file:///System/Library/Audio/UISounds/short_low_high.caf",
"Long Low Short High":"file:///System/Library/Audio/UISounds/long_low_short_high.caf",
"SOS":"file:///System/Library/PrivateFrameworks/ToneLibrary.framework/AlertTones/SOS-Countdown-Tick.caf",
"Spartan Connecting":"file:///System/Library/Audio/UISounds/nano/Alert_SpartanConnecting_LowLatency_Haptic.caf",
"Spartan Connected":"file:///System/Library/Audio/UISounds/nano/Alert_SpartanConnected_LowLatency_Haptic.caf",
"Spartan Disconnected":"file:///System/Library/Audio/UISounds/nano/Alert_SpartanDisconnected_LowLatency_Haptic.caf",
"Timer":"file:///System/Library/Audio/UISounds/nano/SedentaryTimer_Haptic.caf",
"Tink":"file:///System/Library/Audio/UISounds/Tink.caf",
"Tock":"file:///System/Library/Audio/UISounds/Tock.caf",
"Tone":"file:///System/Library/Audio/UISounds/nano/BatteryMagsafe_Haptic.caf",
"USSD":"file:///System/Library/Audio/UISounds/ussd.caf",
"Warsaw":"file:///System/Library/Audio/UISounds/warsaw.caf",
"Fail":"file:///System/Library/Audio/UISounds/nano/3rdParty_Failure_Haptic.caf",
"Retry":"file:///System/Library/Audio/UISounds/nano/3rdParty_Retry_Haptic.caf",
"Start":"file:///System/Library/Audio/UISounds/nano/3rdParty_Start_Haptic.caf",
"Stop":"file:///System/Library/Audio/UISounds/nano/3rdParty_Stop_Haptic.caf",
"Success":"file:///System/Library/Audio/UISounds/nano/3rdParty_Success_Haptic.caf",
"Calendar":"file:///System/Library/Audio/UISounds/nano/Alert_Calendar_Haptic.caf",
"Reminder":"file:///System/Library/Audio/UISounds/nano/Alert_ReminderDue_Haptic.caf",
"Passbook":"file:///System/Library/Audio/UISounds/nano/Alert_PassbookGeofence_Haptic.caf",
"Payment Fail":"file:///System/Library/Audio/UISounds/payment_failure.caf",
"Payment Success":"file:///System/Library/Audio/UISounds/payment_success.caf",
"Acknowledgment Received":"file:///System/Library/Audio/UISounds/acknowledgment_received.caf",
"Acknowledgment Sent":"file:///System/Library/Audio/UISounds/acknowledgment_sent.caf",
"Mail":"file:///System/Library/Audio/UISounds/nano/Alert_Mail_Haptic.caf",
"Mail Received":"file:///System/Library/Audio/UISounds/new-mail.caf",
"Message Received":"file:///System/Library/Audio/UISounds/ReceivedMessage.caf",
"Message Sent":"file:///System/Library/Audio/UISounds/SentMessage.caf",
"Walkie Talkie":"file:///System/Library/Audio/UISounds/nano/Alert_WalkieTalkie_Haptic.caf",
"Walkie Talkie Received Start":"file:///System/Library/Audio/UISounds/nano/WalkieTalkieReceiveStart_Haptic.caf",
"Walkie Talkie Received End":"file:///System/Library/Audio/UISounds/nano/WalkieTalkieReceiveEnd_Haptic.caf",
"Walkie Talkie Sent Start":"file:///System/Library/Audio/UISounds/nano/WalkieTalkieActiveStart_Haptic.caf",
"Walkie Talkie Sent End":"file:///System/Library/Audio/UISounds/nano/WalkieTalkieActiveEnd_Haptic.caf",
"Ringtone UK":"file:///System/Library/Audio/UISounds/nano/Ringtone_UK_Haptic.caf",
"Ringtone US":"file:///System/Library/Audio/UISounds/nano/Ringtone_US_Haptic.caf",
"Ringtone UX":"file:///System/Library/Audio/UISounds/nano/Ringtone_2_Haptic-sashimi.caf",
"Bedtime":"file:///System/Library/Audio/UISounds/go_to_sleep_alert.caf",
"Nightstand":"file:///System/Library/Audio/UISounds/nano/Alarm_Nightstand_Haptic.caf"
}