When you see the headline “bird song and stress”, what does that bring to mind? My initial reaction is to recall the next door’s annoying rooster that used to wake me up at the crack of dawn. Well, that’s not what we’re talking about here. In fact, quite the opposite. Did you know that bird song can mask the annoyance of traffic noise?

The importance of masking traffic noise

As we covered a few weeks ago, the noise stress caused by road traffic noice can have significant and detrimental impacts on humans. Anything that might bring relief to people living near sources of traffic noise should be welcomed!

Multiple studies have shown that the song of birds can actually reduce the stress of unwanted noise. If you’re fortunate enough to be in a park that abuts a main road, you can see for yourself. I recently undertook this experiment myself along Springvale Road—a six lane major road in Melbourne. Anecdotally, this research holds. I felt a lot calmer when standing in a nearby park with birdsong, even though the traffic noise remained.

Comparing bird song and traffic

An example of this effect is a study that studied the masking effect noise of birds chirping on cars passing. As you can see from the diagram below (Fig. 2), the sound of cars passing is lower than the volume of the bird’s chirps.

While the bird’s chirp is at a higher frequency than the car noise, the introduction of the pleasant, natural sound reduces the annoyance of the other (Fig. 5 & Fig. 6, below).

Dwindling bird populations

Unfortunately, road traffic noise has an impact on birds too. With denser urban sprawl comes less trees, and less habitat for birds. As with humans, birds are impacted by noise stress.

For example, the nature of birds to adapt has had the unfortunate consequence of birds changing their songs. In fact, some studies have shown that in urban avian populations like sparrows, bird song has adapted to a higher frequency and volume to combat the traffic noise. Others sound like the traffic noise itself!

Thankfully, where planning laws take into account birdlife, and room is left for expanses of green space and trees, the impact of traffic on birds lessens. In Singapore, where many people keep birds as pets, there are even parks dedicated to bringing birds in their cages to socialise!

But where birds have left at area, or their song is no match for traffic, there are other solutions. For example, Soundmask’s “traffic noise” preset reduces noise stress and distractions from lower frequency traffic noise.