Noise and Sound Control for Better Sleep
Circadian health expert and medical scientist Logan Pendergrast, Ph.D., explains how environmental noise—sometimes as subtle as a refrigerator hum or quiet conversation—can disrupt sleep. Even low-level sounds can trigger micro-arousals that fragment rest, leaving the body less restored by morning.
In this segment, Dr. Pendergrast explores the science of how sound influences sleep quality and shares ways to create a calmer, more stable sound environment. By reducing disruptive noise and introducing consistent soundscapes, individuals can protect their sleep cycles and improve the depth of their rest.
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Well, hello again everyone and welcome
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to lesson four of our night aling
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education series, environmental sleep
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science, engineering your sleep space.
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As usual, my name is Logan and I have a
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PhD in medical science and I'm here
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today to talk to you about how we can
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change our sleep environment so that we
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can become more effective sleepers.
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So, what we're going to talk about
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today, we'll start first with talking
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about how controlling the light of
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course in our environment can help us
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improve our sleep. We'll then move into
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the temperature of our environment and
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the air quality and how that can help us
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improve our sleep quality. Next, we'll
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move into sounds and even the scents in
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our environment and how they influence
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our ability to sleep. And then lastly,
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we'll finish with talking about the
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surfaces we sleep on, meaning our beds
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or whatever mats that we're sleeping on.
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So, why does our sleep environment
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matter? Well, that's a good question. uh
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our sleep environment can influence not
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just how quickly we fall asleep but also
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how well we stay asleep. And for those
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of us who are working shift work, we are
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especially sensitive to these
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disruptions given that we are moving
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around during the times when the sun is
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down. We are exposed to artificial
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lights and artificial sounds that maybe
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individuals who don't work shift work
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don't experience. And there's research
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that's been published to show that about
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90% of the quality of sleep that shift
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workers experience is influenced by
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actually nonbiological factors, meaning
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environmental factors that are outside
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of our typical standard biology in our
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regular clock. But the good news is that
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there are factors that we can influence
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such as the light in our environment or
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even the sounds in the air quality so
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that we can improve our sleep and avoid
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some of these disruptions that are
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commonly associated with working shift
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work. So we'll start here first with the
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most important and likely most alterable
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factor that influences our sleep and
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that is the light in our environment. So
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the exposure um to light in times when
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we are approaching sleep whether that's
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evening or whether that's during the day
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suppresses the release of melatonin and
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melatonin is a hormone that is
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responsible for preparing our body for
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sleep. So if we're exposed to the some
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of these common culprits like our
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smartphones or our video games, our
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television screens or even the overhead
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lights in the room, this will suppress
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that melatonin and will make it more
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difficult for us to sleep. So, in order
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to influence this, there are fortunately
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cheap options that we can implement.
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There are blackout curtains that can be
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purchased online that can be placed over
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top of windows to reduce the amount of
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light that's coming into the room far
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more effectively than, for instance,
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simple blinds, which allow light to pass
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through them, street lights from
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outside, etc. And so, these these
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blackout currents can be quite
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effective. There's also dimmable lamps.
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So if it's the case that we're reading
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in the evening uh in the room that we'll
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also be sleeping in or reading during
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the day in the room we'll also be
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sleeping in then we can dim the amount
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of brightness in these lamps uh so that
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we are reaching the amount of brightness
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that is below the amount that would keep
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our body awake. And in the same vein as
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this there are also smart light bulbs
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that can be programmed to reduce the
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amount of brightness that they emit over
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the course of the day or over the course
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of the evening. so that as you're
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reaching the time where you would go to
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sleep, you are exposed to less actual
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bright light. And one quick tip as well
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that we can utilize to improve the
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amount of light that's in our sleep
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environment or reduce the amount of
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light that's in our sleep environment is
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to swap the typical LED lighting that is
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in rooms and um insert some of these low
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lumen light bulbs. So there's 2700 K as
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this threshold that is considered to be
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low lumens and this should minimally
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disrupt the amount of light exposure
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that we are experiencing as we're
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approaching sleep and can help us
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preserve the function of our melatonin.
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So moving on to our next factor and that
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is thermmore regulation or the
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regulation of the temperature in our
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environment and in our bodies. So just
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to give some numbers, the ideal sleep
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temperature that is supported in the
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scientific literature is 16 to 19
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degrees C, which equates to about 60 to
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67° F, which seems quite cold, but what
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this does is it facilitates a drop in
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body temperature as we reach deeper
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stages of sleep. And this drop in body
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temperature should be about 1° C. And so
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what this does is it allows us to reach
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the deeper stages of sleep, the stage
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three and stage four stages of sleep, so
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that we can have a more effective sleep
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architecture. And what happens actually
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is in these environments where we are
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overheated, let's say on a summer day
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with the window open, we're sleeping. Uh
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it it interrupts our sleep architecture,
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we're prevented from reaching the deeper
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stages of sleep and we feel less rested
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upon waking. So there are things that we
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can implement to facilitate this. Of
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course, there's cooler bedding options,
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sleeping perhaps with a thinner sheet
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rather than a heavy blanket or using
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fans or of course air conditioning to
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improve the amount of temperature that
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we're experiencing to keep it at a lower
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threshold so that we're able to drop our
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body temperature. And then an additional
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tip that we can um that we can utilize
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here that it that helps us hack our
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bodies in some way to prepare for the
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drop in temperature during sleep is to
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take a warm shower about an hour before
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bed. And what this does is it dilates
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the blood vessels in the periphery or
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the outer parts of your body. And when
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those blood vessels dilate, your body is
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better able to get rid of the heat
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that's in it. And so this facilitates us
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to lower our body temperature and sleep
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more effectively.
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So let's talk about our next factor and
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that is the sound of our environment. So
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if you use an alarm clock, you're
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familiar with this. The sounds that we
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hear in our environment can influence
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our ability to sleep. And this is shown
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actually in the scientific data where
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sounds even at about 40 dB like the hum
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of a refrigerator or a quiet
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conversation can increase the amount of
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arousals during sleep or the amount of
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essentially wake pulses during sleep.
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even when those measurements aren't um
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noticed by an electrophilogram
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or the brain measurement device. So
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there are subtle um interruptions to our
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sleep by even small amounts of sound. So
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there are fortunately simple ways that
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we can um improve this. One of them is
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using white noise. So using white or
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pink noise which can be found on
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playlists on Spotify for instance or
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there are sounds um emitting devices
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that you can buy commercially at places
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like you know stores that are commercial
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department stores that are nearby and
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what this does is provides a common
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stable soundsscape so that we aren't
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experiencing interruptions in the
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environment around us in disrupting our
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sleep. Additionally, of course, there
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are earplugs which can reduce the amount
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of arousals during sleep by up to 60%.
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We can also put inserts into our windows
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that can reduce the amount of noise
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coming through that by about 50 to 70%.
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And as a as a takeaway tip here,
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something that we can consider,
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instruments like fans or air purifiers
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provide a dual effect where they are
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either cooling our environment down or
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improving the air quality in our
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environment, but also providing a
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background sound to drown out any sort
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of disruptions in the soundsscape.
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So this brings us to our next factor,
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which is air quality and ventilation. So
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in this science, what we see is that
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when individuals sleep in a high CO2
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environment, what that means is carbon
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dioxide. It's a gas that we exhale, they
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have impaired cognition when they wake
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up. What this means is that their brains
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are less clear when they wake up. So
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what this reflects is is that the
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quality of the air in our environment is
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very important for the quality of our
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sleep. And fortunately, there are ways
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to improve this. There's of course air
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filters which are most commonly and most
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effectively used um are hepailters and
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these can improve the efficiency of our
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sleep by improving the quality of our
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air. There's also plants which are less
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of a help than mechanical filters like
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air filters but they can improve the
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quality of our air. And just considering
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all of this and thinking of tips that
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can improve air quality, there's also
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just the simple method of keeping a
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window slightly open as we sleep. And
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what this can do is just allow for
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exchange of air to our internal and
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external environment, hopefully with
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minimal noise so that we can maintain a
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a more effective sleep quality by just
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controlling the quality of our air.
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So next we will talk about a factor that
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many don't think about and that is the
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scent in the environment that we sleep
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in. So there is some scientific data to
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show that the sense that we are
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experiencing during sleep can influence
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the quality of our sleep. And one of
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these studies showed that lavender which
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is linolu lowers our heart rate and
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boosts the quality of our deep sleep.
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This was published in 2005.
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So, in considering this and considering
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how important the smell in our
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environment could be, we would like to
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avoid some allergenic or some of these
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highly synthetic scents because if
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you're having some sort of an allergen
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that can cause, let's say for instance,
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inflammation in the nose, which could
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impair your ability to breathe.
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Um, there's also evidence that having
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consistent smells in the environment,
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let's say for instance that's lavender,
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can reinforce the body's preparedness
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for sleep through just regular behavior.
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And what this is called is is pavlavian
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conditioning. What this just means is
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essentially habitually your body knows
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that when it smells lavender, it it
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should be prepared for sleep. An
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additional tip here is to skip these
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plugins that plug into the wall. And the
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reason for that is because these plugins
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have what are called volatile organic
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compounds or VOCC's. And these have some
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toxicity effects on the body that could
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impair our ability to sleep effectively.
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And so, as a tip here, maybe to um
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implement for those of us who would like
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to try this out, using a drop of
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something like two to three simple drops
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of lavender oil around the pillow or
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around the surface that we're sleeping
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on could maybe begin to utilize some of
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these factors that are supported in the
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scientific data to help improve our
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sleep. Okay, so let's move into our
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final factor, which is obvious, and that
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is our sleep surface. So, our mattress,
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our pillows, and even our sheets. So
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quite a bit of data has been gathered on
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this and what is found is that the
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firmness of the mattress can determine
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the alignment of our spine as we sleep
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and then also the quality of our
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shortwave sleep. And what the studies
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show is that medium firm mattresses are
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most effective for managing our body's
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spinal alignment and reducing back pain
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which improves our sleep quality. And
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additionally, mattresses that are too
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soft that allow our body to sink too
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deeply into them or mattresses that are
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too firm that resist our body sinking
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into them are considered to be a bit too
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extreme on either end and can impair our
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ability to sleep. So, it's likely the
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case that more moderately firm
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mattresses are the most effective. And
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as a final tip here, because mattresses
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are composed of foam and springs and
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hard materials, these materials can
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break down over years of having body
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slept on them. And so it's most
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recommended to purchase a new mattress
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about every 7 to 10 years so that the
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mattresses are being utilized at their
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most effective form.
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So let's summarize. The environment that
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you're sleeping in can influence the
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quality of your sleep. And so
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controlling factors like the light in
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the room or even the sounds and the
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temperature can really help you to shift
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all of the levers to maximize the
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quality of our sleep. So ideally we are
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sleeping in a dark room that is cool
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with consistent sounds and consistent
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bedding that we're on that is moderately
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firm and then really having an idea of
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this can help us move forward. So those
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of us who are are shift workers, let's
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say, uh are likely more susceptible to
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uh environmental interruptions such as
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sound or let's say light coming from the
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sun. So it's important to have this in
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mind and to maybe even have something
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like a checklist where we have in mind
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that we should be sleeping in a dark
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environment that is quiet and cool so
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that we can go through each of these
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factors, maximize them so that we can
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improve the quality of our sleep and
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become the best human beings that we
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could possibly be.
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And with that, um, that's all I have for
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today's lesson. This is Logan from Night
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Owling, and I will see you next time.