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Capturing Quality Sound with a Cell Phone

Most teachers don’t have access to a professional recording studio. Does this mean their students are doomed to suffer from low-quality audio? No.

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In many digital learning situations, sound is actually more important to student learning than visuals. Don’t take my word for it. Try turning off the sound during a TV newscast and see how much you learn about the day’s events. 

Because good quality audio is so important to student success, it is incumbent upon teachers to do their best to capture high-quality audio for their video lessons, Zoom sessions, audio podcasts, and other digital instruction. Here you’ll learn how to record the very best audio possible — with your cell phone.

Avoiding Microphone Pitfalls

The microphone (mic) in your cell phone is a pretty simple device, yet it does the magic of converting the sound of a voice into an audio signal. Understanding the quirks and limitations of cell phone mics will help you minimize their ill effects. 

For example, microphones are prone to overemphasize wind noise, making a moderate breeze sound like a Kansas tornado. Always try to keep mics away from blustery conditions. 

“Handling noise” is another potential hazard of mic usage. When recording, avoid rubbing or moving your fingers on the phone. The phone case can transfer the energy to the mic, and the resulting rumble isn’t pleasant to the ear.

Microphones used in cell phones are particularly sensitive to distant or quiet sounds. Usually, this is a good thing; this sensitivity makes it possible for you to be far from the phone, yet allows your voice to come through clearly. This is advantageous in many situations but can also be a liability in noisy situations, more on this next.

Let’s look at three scenarios that pose unique sound-capturing challenges for teachers and learn how to overcome the obstacles.

Scenario #1: Welding Shop Racket

A high school welding teacher wants to produce a video that instructs students how to safely use the metal grinder. The goal is to emphasize the sound of the teacher while avoiding the cacophony of noise inherent in the welding shop. 

The best advice in this setting is true in most recording situations: get the cell phone mic as close as possible to the source of the desired sound (teacher’s voice) while reducing the undesirable sound (welding shop noise) by moving as far away as possible from the source of the noise. 

Scenario #2: Street Corner Challenge

Let’s explore another noisy situation involving a 3rd-grade teacher recording an audio-only podcast on a historic — and busy — street corner. Traffic noise is the challenge here. 

The teacher should begin by describing their location to students, this will explain why they are hearing traffic. Just like in the welding shop, the solution here is for the teacher to get as close as possible to the mic while distancing the mic from the traffic noise.

There can be a pedagogical advantage to audio-only content because it engages students’ imagination as they envision the street corner in their mind. This is like the experiential difference between reading a book and watching a movie.

Scenario #3: Crashing Ocean Waves

Another challenging recording scenario involves a middle school teacher who desires to connect with students at the start of the school year. Over the summer, the teacher wants to create a “welcome video” that personalizes them by recording the video on a busy beach, complete with surfers.

In order to get a stable video image, the teacher has chosen to use a tripod to steady the cell phone. They want to minimize their presence in the shot while clearly showing the surfers on the waves in the background. This appears to be a good idea, but will it work? Not well. 

As far as the mic is concerned, the teacher is too far away to be loud enough to overcome the sound of the crashing waves and other beach noises. The mic needs to be closer, but that change will alter the teacher’s creative vision. Is there a solution that doesn’t require compromise? Yes, read on.

Advanced Concepts

Microphones in cell phones do a decent job under the right circumstances, but a higher level of quality is possible with accessory mics that connect to cell phones. Some accessory mics are directional (called unidirectional or shotgun) and do a great job of ignoring unwanted sound coming from a specific direction — like traffic noise or crashing ocean waves. Others attach to a person’s clothing or sit on a desk. Here’s a sampling of wired and Bluetooth accessory mics from Sweetwater.com for iPhone and Android phones. 

It’s worth mentioning that many cell phones have multiple mics — possible locations include the front, back or side of the phone. Additionally, a mic attached to wired earbuds may have come with your phone purchase. Doing some research and experimentation with your cell phone microphones will help you achieve the best outcomes.

Producing video lessons, audio podcasts and other digital instruction makes your content more accessible and engaging for your students. So grab your phone and start experimenting, and surprise yourself with the quality of the result.

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