When we enter a room, meet someone new, or take a walk, it isn’t just our eyes that are forming impressions. Our ears are also hard at work understanding our environment.
We can identify someone based on their voice, understand their feelings based on the tone, and even detect subtle cues about their intentions based on how they talk.
Even when we aren’t interacting with people, the sound around us provides important information like our location in a room, our proximity to a sound source, and how a space is designed.
Why acoustics are important
All these sound impressions are part of acoustics – and they are an essential aspect of a listener’s experience, wherever they are.
Take a hotel, for example. Tall ceilings in the lobby can create reverberant acoustics that signal the arrival of guests. Hotel bars offer more dampened acoustics to give a more intimate and private feel. Concert halls and theatres are also acoustically designed to enhance performances and create an immersive and engaging experience for the audience.
Everywhere we go, the sounds we hear help us learn about, feel, and experience the world around us. And by understanding the underlying principles of acoustics and sound propagation, we can create environments that support hearing, and we can design better hearing technology to help those who cannot hear well.
Hearing the room
How well we hear is heavily influenced by the acoustics of the space and the properties of the sounds themselves. When the acoustics of a space are carefully designed and optimised, we can hear sound the way it is meant to be heard with minimal distortion or interference.
But when the acoustics are poor, sounds may become muddled, indistinct, or difficult to hear. This can lead to frustration, disorientation, and even safety risks. For people with hearing loss, these feelings can occur more often and be more intense.
One crucial aspect of acoustics is how sound is reflected off surfaces in a room. When a sound is produced in a space, it creates many reflections that arrive at the listener's ears at different times. The direct sound travels in a straight line from the source to the listener, while some of the sound is reflected off surfaces in the room, creating early and late reflections.
This illustration shows how a sound in a room reaches a listener’s ears via several pathways. The direct sound spreads straight from the source to the listener. Any other sound is reflected off the surfaces in the room. Because the distance travelled by the reflected sound is greater than that of the direct sound, the reflected sounds arrive at the listener’s ears later and are lower in amplitude.
How hearing aids can help
It is important for hearing aids to replicate sound as naturally as possible so that wearers can feel the acoustics of the room in the same way as everyone else. One way to do that involves minimising the time delay from when the hearing aid detects a sound to when a wearer hears it.
Widex hearing aids have a technology called ZeroDelay that helps maintain the natural sound cues that people use to identify where sounds are coming from in a room. A recent study showed that study participants were better at discriminating listening positions in a room when using ZeroDelay technology compared to other premium hearing aids, which have longer processing delays.
This chart shows listeners’ abilities to discriminate the location in which recordings were made within a reverberant classroom with three different hearing aids. Horizontal bars show significance.
It’s no secret that potential wearers are often sceptical about hearing aids making things sound artificial – especially in the first few weeks they use them. ZeroDelay preserves the naturalness of processed sounds, which helps the wearer forget they are even wearing hearing aids. That might mean greater satisfaction with hearing aids, a quicker adjustment period, and longer use.