Record & Trim Short Audio Clips on your iPhone

Let’s record some short audio clips, just one word or letter sound per audio clip.

If you get stuck or having any qursion, please ask your instructor for assistance!

Step 1

• Leave the receiver plugged in and open the Voice Memos app.
• Tap the red record button, have the speaker say two or three letters, then tap stop.
• Play it back through headphones plugged into or paired with the phone, and listen for clear speech, no crackle or distortion on loud letters, and low room echo.
• If anything sounds off, go back to Mimo in Step 5 and adjust the gain before recording for real.
• Verify the right mic is in use: gently scratch the transmitter capsule during your test. If you hear the scratch loudly on playback, the DJI mic is active. If tapping the phone itself is what comes through, the receiver is not connected properly, so unplug it and reseat it.

Step 2

• Record each letter as its own memo so you don’t have to split one long file later. For each letter, follow the same rhythm: start recording, wait about half a second, say the letter, wait another half second, then tap the square stop button. The waveform should show one clear burst (the letter) with flat, quiet sections on either side.
• Work through the alphabet in order from your printed list, ticking off each letter as you go, so nothing gets missed and the memo list matches the alphabet.
• If a take is flubbed, don’t agonize over it—just stop, delete or ignore it, and record the letter again.
• Keep the speaker’s volume and distance identical for every letter, and resist leaning in for quiet letters.
• For letters with glottal stops or other sounds that are easy to under-articulate, consider recording two takes so a language keeper can choose the better one later. The short, quiet sections before and after each letter also give you room to trim cleanly in Step 9.

Step 3

• In the Voice Memos list, tap a recording to expand it, then tap its title (“New Recording 7”) to make it editable.
• Type the letter as the new name, using lowercase to match the filenames your soundboard expects, for example a, b, c.
• For letters with diacritics or glottal stops, use a plain-text name that matches your app’s file mapping, for example c_glottal rather than c', since apostrophes cause trouble in filenames and URLs. This matches the glottal stop prompt in Step 7 of the Alphabet Soundboard activity.
• Give each recording a descriptive name immediately after each recording session, while you can still match memos to letters by order and by ear.

Step 4

• A soundboard feels snappy when audio starts almost instantly after a tap. Trimming each memo to leave only about a quarter-second of silence before the letter makes a big difference.
• Tap a memo, tap the three-dot menu (…), then choose Edit Recording. Tap the crop/trim icon in the top corner, and yellow trim handles appear at each end of the waveform.
• Drag the handles inward so a sliver of silence remains before and after the letter, then tap Trim to keep only the selected region, and tap Save. Play it back once to confirm the letter is not cut off at the start.

Step 5

• In the memo list, tap a recording, tap the three-dot menu (…), then tap Share. To move several at once, tap Edit in the list, select multiple memos, then share them together.
• Choose AirDrop to send straight to a Mac, or Save to Files and then upload from iCloud Drive or Google Drive on any computer.
• Voice Memos exports .m4a files, so a memo named a arrives as a.m4a.
• Modern browsers play m4a just fine, so the simplest path is to tell your soundboard prompt that the files are named wich .m4a extensions.

Quick troubleshooting

Problem	Likely cause and fix
Voice Memos records the phone’s built-in mic	Receiver not seated in the port. Unplug, remove the phone case, reseat, and redo the scratch test from Step 6.
Levels barely move in Mimo	Gain too low, or the TX is off or unlinked. Raise the gain slider and check for a solid green LED on the receiver.
Loud letters crackle or distort	Clipping: peaks hit the red. Lower the gain in Mimo and re-record any distorted letters.
Hiss or roomy echo	Mic too far from the mouth, or a noisy room. Recheck the 15 to 20 cm placement and turn off fans and HVAC if possible.
Recordings vary in volume letter to letter	Speaker distance or volume drifted. Re-set placement and ask for a consistent, relaxed speaking voice.
Mimo shows no device page	Update the Mimo app and the Mic Mini firmware, then unplug and reconnect the receiver.

Congratulations on recording a full set of alphabet audio files! With a folder of named, trimmed letter files, you are ready to build or update a soundboard. Just mention the file extension you ended up with (.m4a or .mp3) in your prompt so the generated code matches your filenames.

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