Amateur radio operators have numerous modes available for communication but the most common one is voice transmission (phone). This is particularly true for new hams and those involved in EmComm. Whether you’re using FM, SSB or AM phone, getting your voice clearly heard on the receiving end involves proper microphone (mic) technique.
No matter whether you are using a hand mic, desk mic, boom mic, or built-in mic, there are are two primary concerns with microphone technique: distance and angle.
Keep the mic 1-2″ (25-50mm) away from your mouth. Any closer and it picks up wet mouth sounds and/or noise from your face/beard/lips brushing against the mic. These are mainly annoying to the listener but in the extreme may obscure your voice.
In extreme cases with FM radios, it can actually result in over-deviation, which sounds distorted.
If your mouth is too far from the mic, the audio level drops significantly and you may become unintelligible, particularly if there is noise at either end. You also begin to lose some of the dynamic range of your voice so it becomes unnatural. If you compensate for distance by increasing the microphone gain setting, ambient noise gets added to you voice and you also risk distortion due to over-modulation.
In short, listeners at the receiving end don’t appreciate hearing someone who is too close or too far from the microphone. It is irritating and/or hard to copy. See photos below.
Then there is angle. Do not speak directly into the microphone element. At the proper 1-2″ distance this often results in “popping” due to the impact of fast-moving air. This typically occurs when speaking plosive words, usually starting with the letters P and B.
In addition, when facing the microphone head-on it tends to pick up breathing sounds which are usually not intended to be shared. Both popping and breathing are irritating to hear at the receiving end.
To minimize popping and breathing sounds in your mic, hold it at an angle from your mouth. In fact, it is often recommended to speak across the microphone face. In practice this sounds very good to hams listening to your voice transmission.
There are a few internet naysayers who insist that speaking into the mic is best and that speaking across it is not good. Perhaps they are referring to a certain type of desk mic? Regardless, there are hundreds of other references that say otherwise. Not to mention the collective experience of many hams that speaking across the mic is good practice with no downside. If you want to settle the issue in your own mind, team up with a fellow ham and experiment with audio quality at different mic angles.
One last bit of proper microphone technique is to speak in a normal voice. No need to yell unless you’re too far away. Whispering or talking softly doesn’t come across well.