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Podcast Episode 020: Understand the art and science of listening – Cam Hough explains the maths of sound in a concert hall and in an office

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Cameron Hough is an acoustic and theatre consultant with consulting firm Arup, and a freelance music critic. He has over 10 years experience in the acoustic design of a wide range of projects, but has a special interest in the acoustics of performing arts buildings, which combines his technical background as an engineer with his skills as a classically-trained orchestral musician.

He regularly attends performances and continues to play with orchestras and chamber music groups (including as the concertmaster of the Brisbane Philharmonic Orchestra and first violinist of Point String Quartet), and brings an approach to listening from both an artistic and a technical background.

Today, he explains how engineering can improve the way you listen to sounds of instruments and voices, and how you can learn how to create an effective listening environment.

Tune in to learn

  • Cameron talks about growing up and having to be the child who was seen and not heard.
  • He started playing violin when he was five or six, and he has always been interested in sound.
  • Cameron is the concertmaster or lead violin. He is the person who tunes the orchestra at the beginning. He is an intermediary between the conductor and the orchestra.
  • What’s involved when creating music and the maths behind the sound of a violin.
  • Hearing beats when the strings are perfectly in tune.
  • How sound interacts with our ears and ultimately our brains.
  • The interaction of sounds in spaces like auditoriums, concert halls, and restaurants
  • How great listening environments are created through their physical attributes.
  • How to make an impactful office from a listener’s perspective.
  • Taking sound for granted because it is always there. It’s not obvious if you can’t listen deeply.
  • Experiencing a place for the first time and thinking of it as tourism of sound.
  • How it takes practice to train your ears to notice things when you walk into a room.
  • Being filled with wonder when hearing things for the first time.
  • A great conductor has an ability to hear what is happening with several musicians simultaneously.
  • How good acoustics has an element of personal taste similar to wine tasting.
  • Providing a sound experience for people through acoustics and a good environment for sound.
  • Using white noise or introducing extra noise to an office can make things better.
  • Hard surfaces reflect sound effectively. Foam and soft furnishings can absorb sound.
  • The lost listener is not hearing you or engaging at all.
  • Cameron feels he is the shrewd listener, because he likes solving problems.
  • Understanding where a sound is coming from by noticing the time that it arrives at your ear.

Transcript

Episode 20: Deep Listening with Cameron Hough

Oscar Trimboli:                   

Deep Listening, Impact Beyond Words

Cam Hough:                          

We might not think very much about what we listened, and so when you have that, let’s say eye-opening because there’s not a better cliché for it. But once your ears are opened and you realise what more is out there, then you suddenly sort of I guess, appreciate things more and are sort of, more conscious of what you’re missing out on.

Oscar Trimboli: 

In this episode of Deep Listening, Impact Beyond Words, we have an amazing opportunity to see both sides of a listening environment. We speak to Cam, an acoustic engineer and also a lead violinist with the Brisbane Philharmonic Orchestra. Cam talks us through the perspective of what’s involved when you’re creating music, the maths behind a violin, and how the sound interacts with your ear, and ultimately, into your brain. But then we get taken on another, different tour, where Cam talks about the interaction between sound and space such as in auditoriums, concert halls, restaurants, and how listening environments are created when you think about the physical attributes of them. Listen now as he talks about how to make a really impactful office listening environment so that you can hear your callings. Let’s listen to Cam.

Oscar Trimboli:                   

55% of our day sis spent listening. Yet 2% of us are taught how to listen. We’re taught how to read and write, we’re taught how to speak. We’re helped out in how to walk, have you got any theories about why we’re not trained up in how to listen.

Cam Hough:                          

It’s an interesting one, and certainly in my professional role as an acoustic engineer. I would really love if people had much more awareness of sounds, in the way that it does have such a big impact on our day to day lives. I guess, maybe one of the main reasons, is that we’re, we have a tendency to be such visual creatures. Although we do use sound so much for communication, that we take it for granted a little bit, because it’s always there. Whereas, I guess in the analogy of, someone reading and writing, it’s pretty obvious if you can’t read, it’s not so obvious if you don’t know how to listen deeply, because you can get by.

I find it really interesting to walk into a new place, so that we can experience for the first time. I like to think about the tourism in sound, that can be something as simple as walking away from a busy road, and you start hearing how a sound of the environment starts changing as you walk away, then eventually you might hear birds singing. The very slow way that’s our urban noise environment, changes as you go from place to place. It takes a little bit of training to get there, I guess. Becoming used to thinking about, “Well, what am I hearing?” It’s the first question. But also, “So, where am I hearing it from?”

Then once you get used to training your ears in that way, and having a listen, then you’ll notice things like you might walk into a room that has a bit of an echo in it. Then your voice starts sounding different. You’ll walk into the opposite, a room that’s really dead. It feels like the room is sucking the sound of the air, and the way that things sound so much differently in each space. I guess sort of I’m mocking that extra dimension of the way that you listen, sort of really just means that when you feel the wonder of hearing things new for the first time.

Oscar Trimboli: 

What was life like growing up like for you? Where were you born, what was the dinner table conversation like?

Cam Hough:

I’m the youngest of three kids. There’s ten years between the next one up. The dinner table conversation was a lot of people a lot older than me, sitting around and talking, and me occasionally being able to contribute. I think that probably kept ongoing as well, about ten years later when my brother and sister moved out of the house. Again, dealing with adults a lot. I think I was in the situation of having that preverbal, seen and not heard. Listen a lot more than I spoke. Whether it was because of that, it’s something that I’ve kind of lead to me having a bit of interest in sounds. Coupled to that, I started playing violin, when I was about five or six. I still can’t remember exactly why I wanted to play the violin, none of my relatives or anything like that, had really played it.

Something obviously peaked my interest about it. Over the years, first a little bit of practise, then some more practise, and some more practise. You got to the point where I actually started to like the sound that I was creating. I continued to play. When it came to pick what I wanted to do, again, I have no idea where this came from. If you have a look at my year 12 yearbook, along with a very questionable photo, there’s the “What do you want to do?” I put down, acoustic engineering.

I still have no idea where that actually came from. It seems like a very logical thing, for someone who has a very musical background, and also developed through school, an interest in science. That’s a way of combining technology, and the artistic side of things into music. Then I did my degree, started doing some work experience actually at the Arup company where I currently work, when I was 19, then started full time when I was 21. The rest as they say, is history. I have now been working with them for just over ten years full time.

Oscar Trimboli:                   

For those of us who have never been in an orchestra, talk to me about the role of the first violin.

Cam Hough:                          

The orchestra that I’m now playing in, which is Brisbane Philharmonic, I’m the concert master, which is a fancy word for the lead violin. It’s basically the person who is responsible, under the conductor, coordinating what the orchestra is doing. The most visible part of that is the person who tunes the orchestra at the beginning of the concert and at the beginning or any rehearsal. It’s not like a dictatorship, or anything like that. Everyone in the orchestra has their part to play, to avoid it evolving into chaos, the concert master that sort of takes other people’s contributions that helps to sort of bring them all together into a musical whole, that then works with the conductor.

In one way, it was sort of acting as an intermediary between the conductor, and the orchestra. That’s especially the case, if there isn’t a permanent conductor, and you’re dealing with a guest conductor each time. It’s actually happens to be the case with my orchestra, that we work with a different conductor with every one of our programmes.

Oscar Trimboli:

When that magical moment happens, immediately before the performance commences, and in your role, you’re helping the orchestra tune its instruments. What are you actually listening for at that point?

Cam Hough:                          

It’s just listening to make sure that people are picking up the right notes. They’re all tuning to the same A, and everyone’s definition of what’s in tune, is the same. With a really good group of musicians, you start to hear the next level of information. We’ll just use the string instrument as an example, because that’s what I play. You start off by tuning your A string, then to tune the other three strings, you have to do some really fine listening. If the strings are perfectly in tune, you actually get what’s called Beats or Tartini tones. That’s basically where the two notes are in such close mathematical relationship, so on a violin that’s tuned in fifths. The frequency of one string compared to the frequency of another string, should be in the ratio of three to two.

Because there’s that mathematical, quite literally, resonance between the two strings. When they’re perfectly in tune, you actually hear what is called Beats. That’s where you can hear the, “Wow, wow, wow,” the best thing that I can approximate it with the voice. You hear the little interference tones, where the sound of the note does vary. That varies a certain number of times per second. That’s related to, how in tune, or out of tune the notes are. When you first listen to a note, you might think, “Oh, that’s in tune.”

When you listen a little bit more carefully, then you might realise you’re a little bit more fractionally out. Then when you go and hear it a second time, and you hear the harmony of something that is now, perfectly in tune. It sounds so natural and so obvious, that I wonder, well, how did I ever think that that was in tune? Now that I’ve heard what can be in tune. We might not think very much about what we listened, and so when you have that, I’m going to say eye-opening. There’s not a better cliché for it. Once your ears are opened, and you realise what more is out there, then you suddenly, I guess appreciate things more, and are more conscious on what you are missing out on.

Oscar Trimboli:                   

What do great conductors do to listen to the entire orchestra, and the individuals in that orchestra, that maybe distinguishes them from okay conductors?

Cam Hough:                          

I think one of the things that really sets a really good conductor apart, is their ability to just be able to hear what is happening between essentially, 90-100 musicians simultaneously, and just be able to hear, if there is something wrong straight up. Be able to say, “Second Bassoon, you’re slightly flat.” Or, “Whoever has the E-Flat in that chord, can you make it a little bit sharper?” Just be able to pick out one element of very complex sounds. And identify what’s right and what’s wrong so quickly. Whereas most people would have to sort of, “All right, everyone stop, everyone start playing one at a time,” then you will notice the playing, where it starts going wrong.

That’s a very, looking at what’s going wrong approach to a good conductor. There’s definitely a role for that, of the conductor is there to try and work out what the problem is and fix it, and improve it. I think where a great conductor comes into it as well, is they’re a positive thing, rather than correcting a negative. They’re inspiring the orchestras to do better things. They have a vision for the sort of sound they want to create. They’re able to communicate that in a way that helps the orchestra try to understand how to produce that sound.

Oscar Trimboli:                   

I was once told that the difference between a good conductor, and a great conductor is a good conductor focused on the orchestra, and a great conductor is focused on the interplay between the orchestra and the audience. How true is that?

Cam Hough:                          

I think I would agree. Musical performance should have an element of theatricality to it. It definitely should be more interesting than just listening to a CD at home. Even if the playing is objectively not as good as what you are getting on a CD. That’s the realness of being in a real room, listening to real musicians. I think has something as a CD would never be able to replicate.

Oscar Trimboli:                   

How do you think the conductor listens to the audience, while they’re in performance?

Cam Hough:                          

You can sort of hear when the audience is listening intently. There’s a different quality of silence. The cliché is to use, silence is the absence of noise. I guess that’s the narrow definition of it. I think you can hear the difference between it’s a silence, but it’s existing because someone is not saying something. Versus the silence of existing, because someone is concentrating and there’s this intent on not making a sound, because they don’t want to miss anything.

Oscar Trimboli:                   

That takes us naturally to their auditorium, in which the performance is taking place, and your profession as an acoustic engineer. Talk us through a day in your life, as an acoustic engineer, as you stand in front of a concert hall, or maybe a conference centre. Maybe an office space. What do you listening for, what are you looking for? What are you sensing.

Cam Hough:                          

After a concert hall sound, we want to have good acoustics, one aspect of that is understanding, what good acoustics are. From a lot of research, we’ve actually discovered that people have a lot of different tastes when it comes to music, and that’s what good acoustics means to someone, isn’t necessarily the same as what other people will have, whether you can hear the notes clearly, whether the instruments are equally in balance. Whether it’s loud of soft. Whether it sounds like its closer distance. Whether it all sounds like it’s coming from one point on stage, or whether it sounds like it’s much broader and there’s a sense of three dimensionalities for sounds. All those are really complicated things, which different people will value different aspects to that.

Wine tasting is a really great example, there’s an element of personal taste to it. What we’ve discovered from that, is that you can’t necessarily say there’s perfect acoustics, until we can necessarily reduce people’s individual preferences to an equation. We might not be able to optimise that mathematically either. What I like to think of acoustics now, and my role, where it’s designing a concert hall, or another space. Is that we’re actually trying to provide an experience for people. Where the design is a sound environment. In a concert hall, that’s pretty obviously the purpose of the room. In other spaces as well, trying to design, still a good environment for sound. Whether it’s the office where you’re working and you’re hoping not to be distracted be someone on the phone, three metres away, or three desks away from you.

Whether it’s an outdoor space, where you’re doing a soundscape, you want your outdoor environment to sound as good as your indoor environment. The more that we understand the way that our ears works, the more interesting it gets I think. They have this really remarkable ability to keep track of the thousands of sound reflections that arrives at our eardrums when we’re a room. If we hear two sounds arise at almost exactly the same time, either from different directions, our ears are able to combine them into one note. Even though we don’t hear them as two separate notes, our ears are still the process, that they’re coming from two different directions. That means that we feel this… we hear the room as having a sense of space. Even if it’s not being distinct in time.

If we’ve trying to translate that into designing a concert hall, then we’re trying to get this particular pattern of reflections of people’s ears. So that they hear enough early energy either arrives at their ears close to the sound, so that it fuses together, and sounds immediate. Then we want some sound to arrive later and later. That blends together in a smooth sequence that we call [acrid 00:14:46]. Then also trying to avoid anything like echoes, which is sound which is arriving much later, that’s distinct, that can be distracting. It is really a balancing act, you want enough sound to arrive at people, but not necessarily all at the same time. It needs to arrive at a particular sequence from particular directions at one seat. That’s hard enough to do for one seat, then you potentially have to do this for seats in an auditorium.

Oscar Trimboli:                   

How do you balance out other environmental factors? Like a concert hall would have air conditioning. That would also create noise, and how do you balance these dimensions out?

Cam Hough:                          

Yeah, that’s a really big challenge. Going back to what we were talking about earlier, there being a positive silence, and a negative silence. You want to take any other distraction out of the way that people are free to have that level of attention. The positive silence of their own. There’s some spaces like Melbourne Recital Centre, the main hall in there is one of, if not the quietest room in Australia. Hearing a concert in there, is really different to hearing a concert in another space. How that’s achieved, is quite a big engineering challenge. In a space that is as quiet as a concert hall, just sometimes the vibrations travelling through the ground, causing the surface of the concert hall to vibrate, are loud enough to that the won’t be audible. It’s quite typical if you’re close to a rail line, or a tram line, which Melbourne Concert Hall is, there’s a tram line literally out the front.

That the whole auditorium is resting on springs. They act like a floating structure within, and the vibrations of the ground, can’t cross the barrier of the springs to reach the structure where the concert hall is located. It’s obviously a pretty expensive thing to do. You don’t do it lightly. If that’s what’s required to get the level of quiet that you need, then it’s something that the building has to do. Then the air conditioning, the whole design for designing an air conditioning system for a concert hall is a very different approach of an office. It’s about trying to get the air to waft into the space, as quietly at all, where it might be barely moving.

Where it goes through the air conditioning ducts. That means a completely different style of approach, because you need massive, massive air conditioning ducts to get that volume of air, that is moving so slowly, that it’s inaudible. In a concert hall, even sometimes, the sound of the lights themselves is too loud. Hopefully you won’t ever see florescent lights used in a concert hall because they’re too loud by themselves.

Oscar Trimboli: 

I was curious if you had any tips to improve listening in an office environment from the perspective of an acoustic engineer?

Cam Hough:                          

There’s probably three things in most offices effecting how much sound gets between people. One of the first ones is, seems a little bit obvious, it’s can you see them? If there’s line of sight, there’s usually line of sound. That’s why offices that have partition barriers between desks, are usually quieter and have less distraction than offices that don’t. Obviously, sound is only one aspect from that, that benefits from being able to see what’s happening. You don’t really want to go through the days of cubical, and things like that. Where there’s not much connection between people. There does need to be a bit of a balance, between how much you can see things, and how much you can hear things. Sometimes, there’s a trend to have too much visual connectivity, which means that you can have too much acoustic connectivity.

The second one is just how quiet or loud the office itself is. It’s a little bit paradoxical, but sometimes, modern buildings are too quiet. We design a building, and there’s might be a sustainability rating tool, that’s used to design it. That’s used as a point. If the building is quieter than a certain value. That’s an important thing to do, you don’t want the building to be too loud, then that’s annoying, in of itself. They haven’t quite really latched onto the idea, that a building can be too quiet. If you’ve ever been into an open plan office, late at night, you can hear what someone is saying 20 metres away, across on the other side of the building. That’s probably because the air conditioning is turned off, and there’s nothing to get in the way of the sound. What we call sound masking. Sometimes what we have to do in an office, is to actually introduce some sound electronically. A lot of offices will have a noise masking system, where they’re basically playing white noise in the ceiling void or under the floor. That’s a way of just making the office a little bit louder further away from the air conditioning vents. So that therefore, relatively the sound of someone talking is quieter.

Sometimes, introducing a little bit of extra noise to an office can make things better rather than worse. The third one is looking at the reflections and things like that. If there’s big surfaces where someone is listening, that hard and reflective, they will reflect sound very easily. That can be a way that sound can bypass a noise barrier, or bypass the ceiling or something like that, and reflect off the surface. Sometimes putting something on walls, that can soft furnishings, and foams, and things like that, that can absorb sound, can help to improve things, because they’ll take some of these reflections out of the way. Exactly the same thing in a home environment, where you’re listing to the stereo. The stereo is aimed at a smooth flat wall that’s going to reflect sound. That reflection of that sound can distort and interfere with the sound that is coming out of the speakers. By putting some acoustic treatment on the walls, to absorb the reflections, you hear the sounds of the stereo much more clearly.

Oscar Trimboli:                   

Let’s change gears, and talk about the four villains of listening. Which one frustrates you the most we’ve got the lost listener, the shrewd listening, the interrupting listener, and the dramatic listener. Which one of those do you tend to get most frustrated with?

Cam Hough:                          

I think I’m going to go with the lost listener. The other three, they’re at least trying to engage with you in their own way. I think I would prefer to have someone that is at least hearing me, if they’re not quite 100% getting it. Rather than someone who is not hearing me at all. There’s always the possibility that you can turn things around with someone that is at least trying to engage with you.

Oscar Trimboli:                   

Which one of those do you think you are?

Cam Hough:                          

I’ve got to say, I’ve got a tendency to be a shrewd listener. I like solving problems, and sometimes it’s hard to focus letting the question unravel, rather than jumping in with the answer.

Oscar Trimboli:                   

If you were to educate somebody, who had never known anything about creating sound, but to explain it to them mathematically, and how that sound enters the ear. How would you take us through that journey?

Cam Hough:                          

Basically, the way that our hearing works, is that the external part of the ear, which is called the canal, that’s a little radar dish, it’s a scoop and helps us to collect sounds, and get into the ear canal. Over simplifying, but because of our ears being located at the sides of our heads, that’s how we tell the difference to where the sound is coming from. A lot of the way that we understand where we’re coming from has to do with either that the sound is arriving at our ears at a slightly different time. We can tell that it’s coming from the right, because it hits our right ear, a little bit before it hit our left ear. Or, it has to do with, it might be louder in one ear than the other. Once it hits the ears, then travels into the ear drum, then get transferred, by three little bones.

The really interesting thing is that when it hits a part of the ear called the tympanic membrane, that you can think of as a little cone. The cone is tuned to different parts of sound. At the entrance to the cone, is that we can hear high frequency sounds, like treble sounds. As it goes further along we hear low frequency sound, base. It means that high frequency sound basically gets absorbed by the little ear cells, on the ear drum, and they vibrate like little strings, when you hear a sound. That’s how nerves know that something is happening, because the hair cells then send an electrical signal to the brain when they are processed, because of the shape of the tympanic membrane because the low frequency notes the base notes happen at the tip of the cone far away from the entrance, it means that they can actually sometimes interfere with us hearing the high frequency notes.

You can sometimes be in a location that has got a lot of low frequency noise happening, and you can actually find it harder to hear high frequency sounds. Aircraft are a really good example of that. It’s a lot harder to listen on an aircraft, than to converse. That has a lot to do with how much low frequency noise there is on an aircraft. It’s not so much necessarily that the aircraft is loud, it’s also about where it’s loud that makes it so hard for us to communicate in an environment like that. It’s also what makes headphones so effective. Because it’s low frequency noise doesn’t change that many times per seconds, current technology, like noise cancelling headphones, are able to pick up that noise, that is pretty close to concert, and they can generate the inverse of the noise mathematically, so that they can combine together to give you zero. That’s why noise cancelling is really effective for things like aircraft. It’s not quite yet effective for lots of other noise sources, like computers, microphones and processing app aren’t quite good enough yet to deal with that.

Oscar Trimboli:                   

Cam, it’s been fascinating to understand the interplay in your life of listening, a musician, an acoustic engineer. You’ve done an amazing job of educating our audience today. In understanding why the environments that you’ve set up are more powerful for creating deep listening and creating a deep impact. I’ve really enjoyed listening to you today. Thank you.

Cam Hough:                          

Thanks, thanks for the opportunity too.

Oscar Trimboli:                   

What a privilege it was to listen to Cam, and understand the maths of sound. Something I wasn’t completely familiar with, the role of sound waves, and how they’re mathematical. I love the way that Cam explained the interaction of the maths inside concert halls. More importantly how you can make an office environment more listening friendly. Which begs the question, how conscious are you, of the environment you’re in when you’re listening?

Sometimes the conversation is really appropriate for corridor, or a kitchen. More often than not, you want to have an impact beyond words, if you want to listen deeply. A quiet meeting room, where you can collect your thoughts and so can the other person. Without distraction, without a glass wall where you can see out. It’s probably one of the more powerful locations, for you can engage with deep listening.

Oscar Trimboli:                   

Deep Listening, Impact Beyond Words.

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