‘Trash Can’ Sound
Capturing good audio still relies on the laws of physics
The quality of home TV sound has improved with DSP trickery and soundbars plus a large pool of younger consumers who have invested in better sound for their gaming experience.
So there is no doubt that the consumer can now hear bad audio. Home sound for movies, sports, national live programing and gaming generally are higher-quality production, but it seems there are areas where the production quality of the sound is excused for some reason or ignored.
Cable news provides an abundance of content both edited and produced, but much of it is from live presentations. As with all things TV, Covid-19 news capture and presentation morphed into an abundance of home journalists with authoritative credentials, however no skills in the technical production of a broadcast quality “homecast.” When the home journalist is dependent on their presentation and voice persuasion and the audio is subpar it is distracting from the content and bad for their brand.
FRONT & CENTER
The pandemic brought the concept of the home journalist front and center and it did not take very long for them to figure out how to get good lighting from cheap digital cameras; front lighting rings can now be found at your local Best Buy. I think viewers can usually accept the inferior picture quality even with poor lip-sync, but the acoustic nature of audio continues to suck.
Why? Because with all the auto features on your picture capture device—camera, computer, iPhone or tablet, the audio auto gain control cannot fix fundamental audio problems. You could parallel the problems for the home journalist to your dads’ home movie production where the audio and lighting was bad or non-existent.
First, virtually all live, non-studio audio suffers from poor acoustics, because of poor microphone placement and microphone selection, and in the digital world, bad-sounding digital gremlins that live in the circuits. Bad audio comes from a variety of culprits, but is easy to diagnose. Most audio problems are the result of simple physics and not usually taught in journalism school, however most TV Tech readers will know that all sound has a direct sound wave and multiple sound waves after the initial. You have to cut the secondary sound waves out—somehow.
Simple physics tells us that you can alter the acoustics by absorbing the extra sounds or diffusing the offending sounds before they become objectionable. For example, virtually every home journalist is a talking-head in front of a bookcase. If the books are organized in a stair-step fashion, the sound will be somewhat diffused and prevent a direct sound reflection from behind directly back into the microphone. Additionally some blankets should be hung on the sides and front to absorb the sound and reduce and eliminate the “trash-can” sound.
DON’T JUST RELY ON YOUR LA PTOP
Microphone placement is critical for all acoustic capture and is probably the most offending culprit in live audio capture and reproduction. From what I can see, a lot of home-based journalists use the built-in camera and microphone on their laptops; but even if the camera and microphone are only arms length away it is still too far for audio pickup. The microphone captures the direct sound from the on-camera journalist plus all the reflections of sound from the desktop, walls, ceiling and computer screen surface and all different reflection times causing an acoustic soup.
The next step beyond the built-in audio in your streaming device is a USB audio interface which provides one or two audio inputs plus headphone monitoring for incoming Q&A, as you will need an audio sound interface to attach an external microphone to your computer. If you choose a lapel microphone there is always the chance of capturing an abundance of room noise, however the goal is to get the microphone as close as possible to the sound source—your mouth.
I would encourage the use of a hand microphone on a stand in front of the presenter. This type of microphone is good for close voice capture with greatly reduced reflective sounds and is readily available from Audio Technica, Sennheiser or Shure in music stores or online. Besides, a hand microphone just sounds better.
Note—part of the microphone might be in the picture/shot, but should not totally obstruct the presenter’s face. Additionally the USB audio interface gives the presenter a high-quality way to monitor the audio which should be done on headphones. I have seen a few home-journalists using headphones and an external microphone, but this level of experience seems to come from the podcasting community where the sound is usually of higher quality than from live cable news programming.
Even with digital audio, there is both good and bad audio quality. Sound must be converted from the sound vibrations that your microphone captures to a digital audio representation. The analog-to-digital conversion algorithms have a range of settings that have a significant impact on fidelity and amount of data to get into the pipeline. High levels of digital compression can sound brittle and edgy with limited frequency spread in the voice with little low frequencies.
How do you fix this? You solve the problem by educating the home journalist and the broadcast technical/production supervisors. Just because you see the audio coming in does not mean it is usable. First, the producers should reject audio and picture, particularly from regular contributors that are below a certain set standard. Speech intelligibility and fidelity are debatable points of view and perhaps that is why poor sounding audio is tolerated, although I will comment that we are decades beyond the early days of AM radio.
Some networks have put together remote packages for high profile commentators with audio, lighting and instructions, but the home journalist can do a lot to improve their brand with as little as $500 and some knowledge from reading this article.
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Dennis Baxter has spent over 35 years in live broadcasting contributing to hundreds of live events including sound design for nine Olympic Games. He has earned multiple Emmy Awards and is the author of “A Practical Guide to Television Sound Engineering,” published in both English and Chinese. His current book about immersive sound practices and production will be available in 2022. He can be reached at dbaxter@dennisbaxtersound.com or at www.dennisbaxtersound.com.