Why does YouTube change volume?

YouTube viewers have increasingly complained about an issue where the volume on YouTube videos seems to randomly increase or decrease during playback. This unexpected change in volume can be jarring or annoying for users. While YouTube has not directly acknowledged the root causes behind this phenomenon, examining how video volume works on the platform and analyzing user complaints can provide some clues as to why it happens.

How Video Volume Works

When a video is recorded, the audio is captured as an analog signal. This analog audio then goes through an analog-to-digital converter, which samples the analog audio waveform at a certain frequency and bit depth to generate a digital audio file. Common sampling rates are 44.1 kHz or 48 kHz at a bit depth of 16 bits.

This process is called audio encoding or audio compression. The digital audio file contains audio samples at set intervals that can then be decoded to reconstruct the original analog waveform. The encoding scheme and bitrate determine the audio quality – higher bitrates and less compression allow for better quality audio.

For online streaming videos, the raw digital audio usually goes through further compression to shrink file sizes. The most common method is lossy compression, which selectively discards audio data that is less audible to humans. This allows comparable audio quality at much lower bitrates. Popular lossy audio codecs used online include AAC and Opus.

According to Internet Audio Encoding, audio for online videos is often encoded at 64-128 kbps to balance quality and file size. The audio encoding happens before the video is uploaded and distributed.

Why Volume Changes

There are a couple main reasons why the volume can change dramatically between YouTube videos:

First, videos are uploaded with wildly different encoding volumes. A vlogger recording on their phone speaker may have a very quiet original volume compared to a music video professionally mixed in a studio. YouTube sees videos uploaded at a range from – db to 0 db ¹. This means volume jumps are inherent to the different sources of content on the platform.

Second, YouTube applies volume normalization to make the average volume more consistent across videos ². However, this can over-correct and cause sudden drops in volume between videos. So YouTube’s own normalization technology, while well-intentioned, can exacerbate the issue.

User Complaints

Many YouTube users have expressed frustration over inconsistent volume levels between videos on the platform. This issue makes the viewing experience unpredictable and disruptive, forcing users to constantly adjust their device’s volume.

As one Reddit user on r/youtube complained, “Because of how inconsistent audio levels can be from channel to channel, it would be great to get an ‘audio normalization’ feature” [1]. The uneven loudness means viewers never know what to expect when clicking on a new video.

Other users describe the phenomenon as “wildly inconsistent” audio that jumps from “too quiet to blow out your eardrums” [2]. This unpredictability ruins the viewing experience and forces users to constantly adjust volume, which many find frustrating.

Overall, inconsistent volumes have been a common complaint among YouTube users for years. The platform has yet to find an effective solution, much to users’ annoyance.

YouTube’s Stance

YouTube states that it uses advanced audio normalization technology to standardize the loudness of all videos on the platform. According to YouTube, this normalization happens after a video is uploaded and should result in a consistent volume level for all content.

However, many users argue that wide discrepancies in volume still exist between videos on YouTube. There are frequent complaints that the volume significantly increases or decreases when switching from one video to another on the platform (Source: Reddit).

Some hypothesize that YouTube’s normalization technology fails to account for more extreme volume differences, allowing overly loud or quiet videos to pass through unadjusted. Others wonder if amateur content creators upload videos without proper audio leveling beforehand, undermining YouTube’s efforts.

Whatever the cause, inconsistent loudness remains an issue that frustrates viewers and mars the user experience. While normalization helps, YouTube does not appear to have found a complete solution as of yet.

Advanced Normalization

YouTube uses advanced audio normalization technology to balance the loudness of videos on the platform. This includes specialized speech recognition that can detect dialogue and conversations. According to a Quora post, YouTube applies normalization specifically to vocal frequencies in order to standardize speech volumes across videos.

This advanced speech recognition allows YouTube to target just the speaking parts in a video. By normalizing vocal frequencies, YouTube aims to prevent jarring volume shifts when transitioning between videos on autoplay. The normalization provides a more consistent listening experience, especially for speech-focused content.

Workarounds

There are a few workarounds that users have found to deal with inconsistent volumes on YouTube videos:

Some browser extensions can help normalize volume across videos or limit loud sounds. Extensions like Volume Master and Auto Volume Control can analyze videos in real-time and adjust the volume accordingly. These provide more consistent volume control than YouTube’s built-in normalization.

Manually adjusting your computer or device’s system volume is another option. This allows you to turn the volume up or down on overly quiet or loud videos. However, it can be tedious to change the volume for every video you watch.

Using headphones or external speakers can also help, as you have more direct control over the volume level. This reduces the impact of YouTube’s inconsistent normalization.

As a last resort, some users resort to third-party apps or sites to watch YouTube videos. For example, apps like NewPipe on Android allow watching YouTube videos outside of the main app and can provide stable volumes.

Best Practices

There are several best practices creators can follow to encode consistent volume levels in their YouTube uploads and avoid drastic volume changes for viewers:

Use a compressor/limiter on the master track when mixing audio. This will prevent peaks from getting too loud and smooth out overall volume levels (source).

Normalize audio levels to hit a target LUFS level (around -14 LUFS is recommended for online video). Many audio editing apps like Audacity have built-in loudness normalization features (source).

After normalizing, do a final listen-through at low, medium and high volumes to check for consistency before exporting. Volume may still vary slightly between scenes, so smooth adjustments may be needed (source).

When encoding, choose a constant bitrate around 8-12 Mbps for 1080p video to maintain quality. Variable bitrates can cause perceived volume fluctuations (source).

Using these best practices when mastering audio and encoding video will help deliver a smooth, consistent volume to viewers.

The Future

Looking ahead, there are a few promising technologies that could help improve YouTube’s volume consistency issues in the future. One possibility is advanced machine learning and AI techniques like those used in YouTube’s current Stable Volume experiment. As the algorithms behind these systems continue to be refined with more training data, the AI could get better at smoothing out volume differences between videos in a more natural way.

Some experts also point to new audio normalization standards like EBU R 128 which aim to standardize loudness levels across different platforms and types of content. As more companies adopt these standards, it could improve volume consistency not just on YouTube but across streaming services and broadcast media. Additionally, new audio codecs and compression methods designed specifically for online streaming could help minimize sudden volume shifts.

In the more distant future, solutions may emerge that can adapt audio in real-time based on a user’s context, environment and preferences. For example, ambient computing technologies could automatically adjust volume to account for background noise levels. More personalized volume normalization tuned to an individual’s hearing could also be possible. While the tech is still emerging, advancements in this area could eventually lead to an end-to-end volume experience truly tailored to each user.

Conclusion

In summary, YouTube’s volume changes are primarily driven by the video normalization technology used to standardize audio levels across videos. While abrupt shifts in loudness can be jarring for viewers, normalization helps improve the overall user experience. YouTube could potentially improve by fine-tuning this technology and offering more user customization around volume preferences. But overall, inconsistent volumes are an understandable side effect of hosting diverse content from creators worldwide. By understanding what causes these volume jumps and implementing simple workarounds, we can better enjoy the breadth of content hosted on YouTube.