What's in a sound?

Foundations of Amateur Radio

Over the past few weeks I've been having my hearing tested. I've had the opportunity to discuss sound in some detail with an audiologist. Today as a result of a collision between a jar of chilli pickles and a tiled floor I've come to the realisation that sound is important in unexpected ways.

It will probably not come as a surprise to you that sound has an emotional component. Just think of a particular song, or a voice, or something that you've heard previously. The sound of a jack-hammer, or a bell, a horse or a jet, each completely different, impact on your mood. Some sounds are pleasant, others jarring. Some make you feel happy, others make you anxious or even angry.

For some time now I've observed in myself that there are times when I cannot stand sound and other times when I invite it into my life.

For example, if there's a HF radio going in the background and I'm attempting to have a conversation with a person in the shack, the sound coming from the radio causes irritation, to the point of needing to turn it off in order to actually hold a conversation. On the other hand, if there's a contest on, I can sit, happy as a clam, listening to HF all day and night, working out what station is calling, and making contact.

I'm raising this because it occurs to me that amateur radio is unlike broadcast radio where you're expected to actively monitor what is being transmitted. In my experience as a radio broadcaster you're talking into a microphone and the headphones you're wearing are connected to a radio receiver which is tuned to the station on which you're broadcasting. This gives you immediate live feedback on the state of your audio levels.

As an aside, I once witnessed a fellow broadcaster who didn't feel the need to wear headphones. They were blissfully unaware that their voice was being transmitted into silence because the audio fader on their microphone was down.

In amateur radio however, we don't often do such things. We transmit blind most if not all of the time. It's rare that we even hear our own voice on-air, let alone hear it in real time. If that's not enough, using sideband, it's easy to modify the sound of a person by changing the frequency slightly, making their voice either higher or lower, just by adjusting the dial.

It occurred to me that how your voice is perceived by the other station assists in how that station can hear you and make contact.

Using the local repeater is a good but subtle example. If you've listened for a while, you might have observed that there are stations that are easy to understand and others that are not. Sometimes that comes down to individual accents, but in my experience a much larger impact is caused by the actual transmission itself.

Is the microphone gain set correctly, is there any filtering in play, is the station on the correct frequency, is the transmitter using the correct mode and other more subtle things like background noise, speaking volume and distance and direction in relation to the microphone.

We often talk about less being more and you already know that I'm a big fan of low power or QRP operation. Making contacts is absolutely about using the right antenna, the right mode, the correct band and time of day, but the sound coming from your station is just as important.

If you have the ability to use two radios simultaneously, then I'd recommend that you find a way to either use a local repeater, or a cross-band repeater, or even a remote web-based radio, to hear what you actually sound like on-air, live, and experiment with the various settings on your radio in order to test and improve the quality of your voice.

Whilst we as radio amateurs don't standardise our signals, though personally I think it would be a great idea, there's plenty of improvement to be had by taking some time out of your next on-air activity to have a long hard listen to yourself.

I'm Onno VK6FLAB