Hackintosh sound not working mac. But did not work Can anyone help me solve this issue.

Hackintosh sound not working mac A variety of issues can trigger the no sound problem. gg/EfCYAJW Do not send modmails to join, we will not accept them. 1 Downloading/Updating Kext1…. md at master · overcache/hackintosh Jan 24, 2024 · Occasionally, Mac users run into a problem where they can not adjust the sound on their Mac. I tried adding ICH9 audio device, AC97 device, but it doesn't recognize anything. Links that maybe you like:## Codec and Layout ID:https:/ Hey all - I've got pretty much everything working perfectly, except for HDMI audio. After enabling the Mac startup sound, you still can't hear the startup chime when turning on your Mac. No output device is shown and the audio section in hackintool is empty as well. Here is my configuration: - Motherboard: Z390 I AORUS PRO WIFI (rev. 5. Follow these detailed troubleshooting steps to resolve the issue of no sound in Microsoft Edge on your Mac: 1. Mar 20, 2023 · Restore previous backup through time machine from when I knew it was working - Regained some youth, but no sound. Dedicated mute and volume controls are found on audio equipment, such as gaming headphones. Jul 16, 2023 · We recommend visiting the official Apple website or using the Mac App Store on your Mac computer to download the latest version of macOS. There is no sound from speakers, through audio jack, neither the HDMI port. I have no issues recording from the "default mic" using Audacity. Dec 18, 2024 · Now, it’s time to test if the volume on Mac not working problem has been fixed. The solution I had was to add the below configuration in the Vagrant file of the VM and recreate it: Make and receive calls and text messages on your Mac; Use your iPhone internet connection with your Mac; Share your Wi-Fi password with another device; Use iPhone as a webcam; Insert sketches, photos, and scans from iPhone or iPad; Unlock your Mac with Apple Watch; Use your iPad as a second display; Use one keyboard and mouse to control Mac and Apr 11, 2021 · Live Bootable USB: https://youtu. AppleALC). Musicians and sound engineers are usually particularly cautious of this because there are often hardware and software incompatibilities with a new release of macOS. 1 didnt work and I dont use imac smbios. I spent days prior trying many things to no avail. I'm a bit lost about witch kext to use. github. Members Online Agile_Campaign871 Aug 19, 2024 · Native macOS HD audio for not officially supported codecs - Supported codecs · acidanthera/AppleALC Wiki Mar 6, 2024 · Now, let’s explore the troubleshooting steps to address the issue of no sound in Microsoft Edge on your Mac. FINALLY!!!!, after nearly 6 months of tweaking and lots and lots of errors and failures, my machine finally boots, everything Is working, graphics acceleration, touchpad, keyboard, sleep, iMessage etc except sound and wifi, wifi will not work due to incompatible card but I tried to look up some tutorials about fixing sound and tried a few things like adding vodooHDA to the kexts folder but Mar 10, 2024 · I recently installed MacOS Sonoma From olarila. Clear/reset nvram at boot menu. For more information, follow this guide:https://www. 1 and now audio doesn't work with the same used layout id. audio. On all installations below, bluetooth works out of the box and therefore audio / external mouse is a solution to the internal audio & touchpad problems noted. Check System Volume and Audio Output Settings. Jul 28, 2023 · Audio HDMI Audio General Help Graphics Network Hardware Troubleshooting macOS / OS X Updates The Workshop Bootloaders Customization Overclocking Case Mods Completed Mods iMac Mods Mac Pro Mods PowerMac G3 B&W PowerMac G4 PowerMac G4 Cube PowerMac G5 Others Retail Cases Modders Tools 3D Print Resources Jul 15, 2024 · I have successively installed the 3 beta versions of Sequoia (Olarilla editions), and each time everything works fine except for the audio. 9. VoodooHDA was being used for a long time to enable the Audio on macOS. Fix Can’t hear sound from your Mac speakers. 3. Test sound. kext. You can simply restart your Mac to check if the sound returns or not. So I've been trying out all the layout ids and none of them are working. It used to work with Sonoma with the boot arg "alcid=1". https://tinyurl. I have an idea, that I didn't bother to test, since I never needed audio in the guest, but that maybe helps you: I use audio routing interfaces (e. config/new_pulse_conf Reboot your PC. Do you any solution to have sound without passing my headset to the VM ? Instead, some computer motherboards have "nonstandard" audio codecs, which don't work with the normal Realtek audio drivers included with Multibeast. 1 Dec 3, 2024 · Sometimes, your Mac runs into temporary errors, making the enabled Mac startup sound not work. Stay up to date: https://goo. The issue was when connecting my Yamaha P-125 keyboard via USB midi the audio was intermittently glitching. We strongly recommend that macOS users update their operating systems to version 13 or later to take advantage of audio-sharing capabilities. Usually, the user will notice that the sound is not working and/or the sound icon is greyed out. Click the Spotlight search icon and search for “Terminal. x/6. Also, the system takes a long time to boot. So far this is the only solution that worked for me, and it works reliably again when I lose audio and I restore it with this technique. AppleALC, Lilu and AppleHDA are all installed too. It should be working. techy. I can see my mic input in the MacOS audio panel. To check whether you have an unsupported Audio Device, follow the steps below. What works Jul 2, 2024 · 7 Ways to Fix Google Chrome Sound Not Working on Headphones Basic Fixes Restart Chrome: Restart Chrome, reload the tab, and restart your PC to eliminate temporary bugs and glitches. Jul 3, 2022 · Go to System Preferences and uncheck Mute next to the output volume slider under Sound > Output. (You may need to scroll down. I'm using an RME audio interface, but still having the same issue. kext * Extra Info: I have issues with Audio. What doesn't work? Hi. /r/MCAT is a place for MCAT practice, questions, discussion, advice, social networking, news, study tips and more. I can use a program called Piezo to record audio as well, even the Signal messaging lets me record audio messages without issues. 3 Ways to Fix Jul 26, 2024 · This seems like a very random problem, but I am experiencing problems with the sound when on Teams. io Jan 7, 2017 · It's been 4 days now that I really searching to make my sound working on my configuration. apple. Then delete them. 4 and during a check i noticed that the audio didn't work. there are no output devices when going into settings > sound, and Hackintool also does not show any sound devices. Port. Apr 2, 2022 · A few users that update to macOS 12 Monterey notice their sound not working on their Mac. For support, visit the following Discord links: Intel: https://discord. I tried to do the steps suggested by Dortania Post Installation Guide and other solution that i found on internet but nothing solved the problem. be/fHKku8nJBO4Commands:sudo dmesg | grep sndlspci -knn | grep -i -A4 AudioHackintool: https://github. Monterey Spatial Audio Not available (M1 MBP) - is the same for any source (Apple Music / Safari etc) - Anyone have any fixes? Thank you!! upvotes · comments It lead to one result: The VM audio worked on one Mac, but not the other. These common problems and solutions will help you troubleshoot and fix audio problems on your device. Jul 27, 2023 · internal speakers not working Mac or no audio sound when you playing online video on browsers like Safari, Google Chrome; External speakers not working on Mac or annoying popping noise when playing Noise volume or video. Updated to open core to install Big Sur 11. ) Open Sound settings for me. I sincerely apologize for the issue you experience with your Teams notification, I am a user myself and do not work for Microsoft so I understand how frustrating this is. Just recently my sound volume control is not working. but macos tells me there is no sound device. This article explains the common causes of sound not working on a Mac and how to fix them. No Realtek ALC neither the Radeon HDMI Audio. Give macos some minuts to reload sound. 14. I have installed Lilu. Resetting the low-level Mac audio API, Core Audio often resolves these problems. Apr 19, 2019 · I had the same problem as you with a 2019 27” iMac with Windows 10 (1809) on external SSD with no sound to speakers or headphones. I've gone through all 16 layout id's shown at the AppleALC wiki for the ALC1220 chipset, and no joy. Jun 26, 2020 · This method is not working: $ sudo apt-get remove --purge pulseaudio $ sudo apt-get install pulseaudio $ mv ~/. Feb 15, 2021 · Audio HDMI Audio General Help Graphics Network Hardware Troubleshooting macOS / OS X Updates The Workshop Bootloaders Customization Overclocking Case Mods Completed Mods iMac Mods Mac Pro Mods PowerMac G3 B&W PowerMac G4 PowerMac G4 Cube PowerMac G5 Others Retail Cases Modders Tools 3D Print Resources May 4, 2021 · Audio on the emulator of my Big Sur Mac works for me. Bluetooth not working (not as worried about that, removed the kexts for now) audio isn't working (bigger issue, Apple ALC kext is installed) -- with that said, I am able to change the volume, and Mac shows as though it is outputting audio, but no speaker activity I want to add my tuppence worth for anybody else scouring threads like this for possible fixes. Speaker is nice and fine but internal mics is the one not working. Nov 27, 2013 · Audio works perfectly with Clover Bootloader with layout-id 6 using Applealc. 15. com/y6vh5aqy2…. Members Online Agile_Campaign871 Jan 8, 2022 · I have purchased two Mac Mini 2020 with M1 Chips - No sound from HDMI cable to monitor I have purchased two Mac Mini 2020 with M1 Chips - No sound from HDMI cable to monitor. Hackintosh sound Apr 14, 2021 · When the VM was running, the sound on the host was cut off, I couldn't play any sound and restarting the sound driver didn't do anything. 5 Moderators: Cat_7 , Ronald P. Let's go through some of the more common fixes for the sound not working on macOS 11 problem. 0) - Processor: Core i5 - Audio: ALC1220-VB Enhance 114dB(Rear)/ 110dB(Front) SNR in Microphone with NICHICON Audio Capacitors Sep 18, 2024 · Before you post check the Troubleshooting guide here, Dortania Troubleshooting. Good enough for daily use. Oct 23, 2022 · For more information, follow this guide:https://www. kext, AppleALC. I tried Mac Diagnostics but it came normal. Here's the weird part: If I create a new track, audio is fine. 0, MacOS Mojave. Quick look: Whatever media player you are using on Mac, check the volume Mar 21, 2022 · catalina (10. Sound comes out, the mute button works, and using the volume slider will mute the sound and turn it back on, but the volume will not Oct 3, 2024 · Whether you're playing a game, listening to music, or streaming video, you need to be able to hear sound coming from your Mac. plist Reboot pc. Blue tooth. gg/u8V7N5C, AMD: https://discord. Mar 16, 2023 · Hi, i have a problem on my hackintosh with ventura 13. then set flag alcid=, one by one through all supported layouts and no On-board audio Realtek ALC221: Not working on Mac OS X Leopard and Tiger! Consider using a USB DAC headset/speaker for audio funcionality. Sound. the audio is my main issue. AUDIO CONTROLLER - Codec Audio Realtek ALC3234 WORKING: AUDIO TROUGH INTERNAL SPEAKER HEADPHONES - MIC (Not tested but detected in audio settings) MORE INFO IN MY GUIDE. It works in Win 7 It's registered all the sound components eg. This guide can be used for Hi guys recently i updated my hackintosh to sonoma by software update in settings and the sound has gone i tried the voodoodha solution but it doesn't work See full list on dortania. Click Output. I will just connect a bluetooth headset for teams meeting etc. 5 mm Audio to work properly. But it isn't working for me. And, if the sound on your Mac has stopped working, you want to fix it right away. Bluetooth works and AirPods audio work in chrome but not in settings, I think I have to do the DRM I verified it's working by connecting my amp. plist if that helps. I updated my system to Sequoia yesterday (info of my system can be seen in my signature). Note: Asking for help with an EFI is not against the rules Feb 16, 2023 · hello, I installed macos ventura on my system last night. how/tutorials/mac-os-no-sound-problem-fixA short tutorial on how to fix general sound issues and th Jul 15, 2024 · Hello Pravinda , My name is Jackson and thank you for your question. x/5. You need to troubleshoot the issue step by step, read AirDrop not working on Mac. ” Mar 3, 2020 · For me, audio output is not working either (VirtualBox versions 6. I use a MacBook Pro. - AppleALC. macOS Sequoia AirDrop not working. 1. 5. the sound panel shows the monitor but when sleeted no sound come from the HDMI Cable to monitor. Many times, if you face a MacBook Pro speakers not working type of issue, the solution is fairly simple. how/tutorials/fix-microphone-not-working-mac-os-venturaA short tutorial on how to fix the problem w Jul 1, 2020 · Sharing audio from applications and games is supported on macOS 13 and above. More specifically, several Mac users have reported that they are unable to change/adjust sound/volume. On your Mac, choose Apple menu > System Settings, then click Sound in the sidebar. I already tried all the layout id available for my codec and tried to patch with hackintool and audio works on every codec with bad quality except for layout id 66 and 71 but in none of the layouts the microphone works. 8. To fix this: Go to devicemgr in the Windows guest VM, right-click to the sound device, disable it. In this article, we’ll tell you how to fix this sound problem on your Mac. Fortunately, the mysterious missing sound output issue is incredibly simple to fix, and there is nothing actually wrong with the Mac. Jun 6, 2024 · How to Fix the 'Sound Not Working on macOS Big Sur' Issue. config/pulse ~/. , and the hostile behavior of reddit's CEO, /r/DJs is locked until further notice. These sources will So it might be DRM issue, im not sure, but that was my fix, turned a peasant NUC into Mac Pro 6,1 trashcan and all was good, mac mini 8. Airport Kext didn’t work as it is unsupported so changed to heliport and itlwm kext. 100% working Vanilla, Easy & Fast Solution. Troubleshooting Steps to Fix No Sound in Microsoft Edge on Mac. Do you think that your Mac’s volume control is not working? If you can’t adjust volume, here is how you can fix: Please complete each step before moving on. Ensure that the Mac’s Audio is not muted. Mac OS should work now with the accelerated graphics with the latest version of WhateverGreen. By any chance is the volume on your emulator turned completely down? Also, have you tested alternative sources of sound, such a YouTube video playing in the Chrome app to see if those work? No additional permission needed to play sound. Sep 18, 2024 · 2. Mac sound not working still? If no apps interfere with your Mac’s sound output, nothing is plugged into the headphone jack, USB, or Thunderbolt ports, and your sound still doesn’t work, the next step is to restart the sound So I just did my first hackintosh on my Lenovo ThinkPad T440 laptop where i installed Big Sur with OpenCore 0. Sound Settings Hey guys I hope you can help me, I build my first Hackintosh this week. But I cannot get sound with HDMI on my monitor and my hackintosh cannot wake up after sleeping (black screen). I came across a similar issue in tonymacx86. x, High Sierra host and guest). internal speakers, line in, line out ect. Then boot normal. Works with all systems and codecs. com. But if I set up the meeting, the sound is perfect. . It is not working at all. You can try to use Terminal to force I got my HP 440 G7 audio out working. I added an ICH9 audio card and it works but I need to passthrough my USB headset. Mar 1, 2015 · A few Mac users that update to Mac OS X discover their sound and audio output has ceased to work, leading to a completely mute Mac that does not respond to the volume keys. 5 installation on my Dell Latitude E5280. Followed the Comet Lake Laptop Guide except in my boot args I use alcid=3. If someone sets up a meeting with me, they can hardly hear me (I can hear them fine) the only way for them to hear me is to use headphones rather than the internal speakers. I also tried reinstalling everything without any success. Enable Mac startup sound in Terminal. I tried various other id numbers for alcid but no luck. The External Audio Devices Troubleshooting. Nov 29, 2019 · No audio on pre-programmed midi tracks in logic 10. I guess it's because I'm using ready Oct 9, 2023 · I'm in the same boat. PROBLEM: I did a successful installation of macOS Big Sur 11. iShowU Audio Capture, NoMachine Audio Adapter), so I have multiple audio interfaces for the VM to connect to. I'm really lost now because I've tried so much things with all this kext but I didn't succeed to have audio on my motherboard. com/yamzbgd6InstallationGo to t Feb 7, 2024 · However, do not worry – in this guide, I will cover all the bases to help you fix the sound not working problem on your Mac. Make sure [Mac model] Speakers is selected, the “Output volume” slider is not all the way to the left, and the Mute checkbox is not selected. Please visit our channel and take a look at some of our newer videos. Sometimes when you press the volume controls, they appeared to be greyed out, or there is a red light beside the headphone jack. I need your help for these. I have switched cables. I'm using a Gigabyte Z490 Vision G board and a Radeon 5500XT GPU - below is my config. Nov 7, 2024 · MacBook sound issues can be frustrating. com/headkaze/Hackintool I used terminal to force download the installer and let it install on the same disk as Ventura. The MCAT (Medical College Admission Test) is offered by the AAMC and is a required exam for admission to medical schools in the USA and Canada. Mic is working, checked sound settings no luck. 6 days ago · Issue 17. Edited Jul 15, 2021 · 4. , the culprit behind the AirDrop not working issue could be faulty settings, unstable or poor Wi-Fi connection, disabled Bluetooth, Firewall, and so forth. * What files/config I am using: EFI Folder, Lilu. Oct 18, 2023 · the sound output shown by the Sound widget follows, but not always, sometimes it just gets stuck trying to select the headset, otherwise it completely freaks out and shows a crossed speaker icon; sound output and input in apps like Slack, Teams and Zoom gets completely messed up. With that said, let us now skip the small talk and get straight to the solutions. Within Windows it works just fine, so it seems to be a bug with the hackintosh driver. DeviceSettings. For the most part, it is not easy to identify the precise cause. Install all available Aug 30, 2023 · Mac users may experience issues with playback and sound, such as audio randomly stopping or not working at all. 1. The audio codec is ALC269VC. I also noticed eventually that any audio playing out to keyboard was glitching REALTEK ALC256 AUDIO I've successfully booted BigSur and everything is working flawlessly except audio. Nov 17, 2023 · By following this guide, you'll be able to enable Audio on macOS using Clover or OpenCore Bootloader. In protest of reddit's recent decision to eliminate apps like Apollo, RIF, Sync, Boost, etc. No sound on turning on the macbook. Regensburg 6 posts • Page 1 of 1 How to Enable Chime Sound on Hackintosh | macOS Big Sur. Nov 20, 2020 · On top of this, the monitor speakers are rubbish sound - really quiet and tinny Possible solution: The monitor has a earphones “sound out”. Everything else works. 2. Reply reply sambawizard May 12, 2021 · If your audio problems continue, there may be an issue with one of your Mac’s audio interfaces which can result in various bugs, including missing or distorted sound. And there is no sound from internal speakers. In this case, your only option may to be to install VoodooHDA, the notoriously unreliable Hackintosh sound driver known for its poor sound quality (and tendency to cause kernel panics). OpenCore generated boot chime and audio assist) and are unrelated to any configuration needed for OS audio support (e. 1: Mic doesn't work; all other things work perfectly except this. Normally, the Audio Codecs found on Non-Apple computers do not work OOTB when using OS X/macOS, unless its an USB Audio device. kext and AppleALC. What doesn't work? I verified it's working by connecting my amp. 0) - Processor: Core i5 - Audio: ALC1220-VB Enhance 114dB(Rear)/ 110dB(Front) SNR in Microphone with NICHICON Audio Capacitors Go to /Library/Preferences/Audio Take backup of these. But WiFi + Bluetooth and Audio are not working on my system. Everything works fine except for the audio. These problems can occur with any browser and can be frustrating. Then enable it. Reinstall current OS - Mac felt fresh, but still no audio; Try numerous 'sudo' terminal commands, to delete files in HAL folder of mac that affect core audio, amongst manually doing this - Gained some space for more selfies, but no I got my HP 440 G7 audio out working. Pre-baked EFI posts will be removed as they are not guaranteed to work and they spread a low-effort sentiment in the Hackintosh community. 0. 0 up to Mac OS X 10. Now unfortunately it is not even recognized in hackintool. g. Restart the sound controller. Either they freeze or the headset dispears from the drop-down option Feb 2, 2022 · About Qemu-system-ppc, a PPC Mac emulator for Windows, macOS and Linux that can run Mac OS 9. Start by Sep 18, 2024 · 2. gl/t7F2DQ=====🎖 Become our C Mar 17, 2016 · This article aims to help you troubleshoot and fix sound problems. The signal is simply modified by the driver before it is sent out. Fyi, I updated to AppleALC v1. Oct 9, 2018 · In 5 minutes you get your sound on Hackintosh up and running. I wait 2-3 minutes after coming to Apple logo. I've attached both boot loader EFI folders if someone can take a look. com with mod efi folder of NoteBook TigerLake Tigerlake from this link Everything Working fine except Audio I tried Every possible things available on Internet like Changing ALCID Etc. Jul 15, 2024 · I have successively installed the 3 beta versions of Sequoia (Olarilla editions), and each time everything works fine except for the audio. Got an almost perfect working MacBook Pro (Air?). If you are facing an issue with sound not working on Mac issue, the first thing to check Minimal Clover Config and Drivers for Gigabyte Z390 I WIFI - hackintosh/post-installation-fix-audio-video. My DND was off, but I toggled it on and then off again and all of the sudden my alert boxes and sound notifications started working again on Mac Sonoma 14. I have the Realtek ALC 1220. ResetTrafficClass) settings in this section are for UEFI audio support only (e. There is no show-stopper issue with my Mojave 10. Anyone got any idea how I fix this? Here are my build specs: eVGA GeForce GTX 670 FTW Signature2 Mar 26, 2023 · This video is old and is no longer useful. plist com. What I have tried so far: After carefully reading the guide for two days and watching a couple of YT videos I triple booted my HP Pavilion Power Kaby Lake i7700 HQ laptop and all basic things are working fine except for Sound and my external USB Mouse( I haven't mapped USBs yet so that's why I guess). To divert the sound away from the monitor, and onto an external sound unit, which has volume But in the installer I can see a few things that work like mac os recognizes the battery (the percentage and when plugged into the charger), more or less the graphics card (graphics acceleration doesn't seem to be there and only works in hdmi because when I use the deck screen it makes artefacts and its not usable), no wifi, I don't know if the If you would like to share your work, document the specific items required to build your Hackintosh that were not covered in the guide instead. Will this work - If I plug a cable into this, and connect to earphones / or external sound unit? I. If the sound icon is grey, the volume can not be adjusted. Why are the MacBook Pro speakers not working while headphones are functional? This issue often stems from incorrect audio output settings. Sound Not Working Due to Major Updates and Third-Party Apps Third-party plugins that integrate with your Mac can cause the sound to not work properly. And am very happy with it, I just can get the sound to work I OSX. MaLd0n please help me get headphone /3. To be clear, it is the volume control -- both the keyboard control AND the audio control dialog. SystemSettings. BT audio is fine, headphone jack is working. - CA0132. I have the intel i211 which was working ok with Sonoma. Coolers are running after moving mouse or pressing keyboard so probably hackintosh can’t wake monitor. debug_24563. When the AirDrop not showing, transfers files slowly, etc. I installed MacOs Sonoma and it was having sound and then Beta 2 update came on 24th June and after the restart I was watching YouTube video and suddenly audio stopped. Left it for 30 mins and came back with Mac OS Sonoma booted up. e. zip. 7) sound volume control not working Hello. com/ya657fxlChecking Codec3…. Came here researching general notifications missing. However, VoodooHDA was not the perfect solution for Audio and it had problems such as stuttering, and a low level of audio volume as compared to Aug 6, 2018 · Headphones work even when jack is fully inserted, but distortion starts after sleep-wake. 5 I am not getting audio input, nor are the faders showing audio on Logic Pro X 10. Native Intel Wifi. 8. On two hackintoshes here I cannot change the volume at all, they both have the typical Realtek chip with AppleHDA and Lilu to make audio work. UEFI >> Audio: Unless documented otherwise (e. I used the ready EFI File I found on the forum during the installation. ACPI Plug Fix (with hda-verb) is ineffective. everything works apart from my brightness slider and my audio. Almost everything working - WiFi, Bluetooth, Apple keyboard, sound with headphones, microphone. I have successfully Hackintoshed my Lenovo Thinkpad Yoga (Intel i5, Broadwell, Intel HD 5500, 16GB RAM) with Monterey. Are you using an M1-based Mac? I have a hackintosh laptop that I'm connecting a second screen to using a hdmi cable and I'm getting a curious issue it works completely fine for 2 or 3 seconds with sound on the monitor working and no colour tint but then it goes black and comes back washed up with green a green colour tint and no sound working I'm confused as it was working in the past any suggestions would be appreciated In this video I wanna show you how to fix Audio and Microphone your Hackintosh using AppleALC method. But did not work Can anyone help me solve this issue. Hello to you all. By following and implementing all the above steps, you still might not be able to get the digital Audio working and that could be due to an unsupported Audio Device. The #1 social media platform for MCAT advice. After a lot of Google searches I started to suspect a problem with the High Definition Audio Device (not the AMD one, if you have one) in the Device Manager (Sound, video and game controllers) due to it using a standard Microsoft driver. I know that there is 3 kexts relating audio : - AppleHDA. I did a successful installation of macOS Big Sur 11. ugas ngcqe ehezo zmj kfi mmsrhe sfnm ekpj bils vcovo