THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 1

The Effect of Apple Alarm Ringtones on Heart Rate

Adwita Sutradhar

Advanced Research in Science—Biomedical Academy

Mr. Roger Rabold

April 26, 2024

 THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 2

Abstract

The goal of the following experiment was to analyze the effect of various Apple alarm

ringtones on a subject’s heart rate. The ringtones specifically included in the experiment

were Radar, Signal, Sencha, Chalet, and Sunny, It was hypothesized that Radar and

Signal would cause a person’s heart rate to increase, whilst Sencha, Chalet, and Sunny

would decrease the heart rate. This experiment was conducted by having a participant lie

down in a quiet room with headphones on. Next, the subject closed their eyes and their

resting heart rate was recorded. All heart rates (bpm) were recorded using a pulse

oximeter. After a minute, the alarm was played for twenty seconds, and then the new

heart rate was recorded. This process was repeated four more times, with a different

alarm played each time, for 18 subjects. A TTEST was conducted to test for statistical

significance. The respective P-values for Radar, Signal, Sencha, Chalet, and Sunny were

0.007514, 0.607932, 0.355124, 0.240661, 0.374321. As a result, only the data for Radar

was statistically significant, and therefore, the alternative hypothesis for Radar and the

null hypotheses for the rest can be accepted with a 95% confidence level. So, it can be

supported that Radar will increase the heart rate of an individual while the others will

keep the heart rate the same. The data found in this experiment can help scientists further

research the implications of noise on sleep, as well as help Apple and other companies

continue to create ringtones that will be perfect for the morning by helping an individual

lower their heart rate and relax. It will also help individuals ensure that the alarms they

choose won’t contribute to future health problems and help them start their day right.
THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 3

Table of Contents

Abstract……………………………………………………………………………………2

Chapter 1……………………………………………………………………..……………4

Chapter 2……………………………………………………………………..……………5

Review of Literature……………………………………………………………....5

Summary…………………………………………………………………………10

Hypothesis……………………………………………………………………......10

Chapter 3……………………………………………………………………..…………..12

Methodology……………………………………………………………………..12

Data Information………………………………………………………………....13

Chapter 4……………………………………………………………………..…………..14

Statistical Test Results…………………………………………………………...15

Chapter 5……………………………………………………………………..…………..16

Discussion & Critical Evaluation……………………………………………..…16

Closure……………………………………………………...…………………....19

References……………………………………………………………………………..…21
 THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 4

Chapter I

Problem Statement: How do standard Apple alarm ringtones affect a person’s heart rate

while listening to one while resting?

 THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 5

Chapter II

Review of Literature:

How do standard Apple alarm ringtones affect a person’s heart rate while listening

to one while resting? Waking up is one of the hardest things for people to do in the

morning. As a result, many people opt to wake themselves by using an alarm in order to

jolt them awake. During sleep, the human body is still aware of its surroundings. The

brain is always processing the sounds that the ear collects. Normally, when humans hear a

sound, the body will react and signal the heart on what to do. But how does the sound of

an alarm after a silent environment affect a person’s heart rate? Chapter 2 will discuss

how the heart and ears work, the autonomic nervous system, what the body does during

sleep, and related case studies.

The ears are paired organs responsible for auditory function in the human body.

The ear’s job is to carry a sound and transmit it to the brain to be recognized and

remembered. The outer part of the ear, or the pinna, collects the sound waves and

channels them through the ear canal. Then, the waves travel to the eardrum, creating

vibrations that pass onto the ossicles: three tiny bones called malleus, incus, and stapes in

the middle ear. The ossicles further amplify the sound and send the sound waves into the

cochlea, a snail-like structure filled with liquid, within the inner ear. When sound waves

hit the cochlea, the fluid ripples, causing hair-like projections called stereocilia to open

up. The stereocilia takes the chemicals and creates an electrical signal. Finally, the

auditory nerve carries the signal to the brain for processing in the auditory cortex (U.S.

Department of Health and Human Services, 2015).

 THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 6

One of the most crucial parts of the human body is the heart. It is a fist-size organ

responsible for pumping blood through the body, using a system of arteries and veins. A

heartbeat is the contraction of the atria and ventricles. Creating a heartbeat can be

simplified into two steps. The first step is called diastole. First, blood collects in the

heart's upper chambers (the right and left atria), and the SA node creates an electrical

signal that makes the atria contract. Then, blood rushes into the lower chambers (the right

and left ventricles), and the valves between the two chambers close. The second step is

called systole. The blood-filled ventricles begin contracting due to the electrical signal

from the SA node. The aortic and pulmonary valves open, sending blood throughout the

body and lungs (The Texas Heart Institute, 2020). A pulse or heart rate is the number of

times a heart beats per minute. Factors like physical activity, stress, body position, and

more can influence how fast or slow a person’s heart rate is. A healthy resting heart rate

averages 60 to 100 beats per minute (American Heart Association, 2023).

Another factor affecting heart rate is the autonomic nervous system (ANS). This

system controls functions the body needs to survive and processes a person does not

actively control. ANS is active both during sleep and wakefulness. The parasympathetic

nervous system (PSNS) and the sympathetic nervous system (SNS) are two parts of the

ANS. The PSNS’s job is to reduce the activities of the body. When the body feels relaxed

and safe, the PSNS lowers the heart rate or returns to its standard level (Cleveland Clinic,

2022a). Meanwhile, the SNS takes the lead during times of need, specifically during

stressful or dangerous situations. It is responsible for the “fight-or-flight” response from

the body. The SNS will increase heart rate to increase the amount of oxygen going to
 THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 7

other parts of the body. Factors that can affect the SNS include stress, overstimulation,

and noises (Cleveland Clinic, 2022b).

Even while asleep, the human body is still active. When people sleep, their brains

will cause them to be less aware of their surroundings, but the brain will continue

working on processing new information and repairs (Cleveland Clinic, 2023). Hearing is

an involuntary action, but when people are asleep, the brain reduces the processing of

sound based on their sleep stage. The sleep cycle can be split into light sleep, deep sleep,

and REM (rapid eye movement) sleep. Light sleep, consisting of nREM (non-rapid eye

movement) 1 and 2, is when people begin falling asleep or waking up and are still aware

of their surroundings, including sounds. During nREM 3, also known as deep sleep, and

REM sleep, a person is unaware of audio. However, the brain can identify certain sounds

and signals for someone to wake up, like a baby crying, and can grow accustomed to

sounds, like a fan. Every night, the average person completes four to six full cycles, each

cycle lasting from 80 to 100 minutes. Waking up in the middle of the cycle can cause

people to have poor emotional and cognitive performance (Mayer, 2023).

A study conducted by Dr. Thomas Andrillon at PSL Research University

discovered how people respond to their environment while asleep. There were 23

participants aged 21 to 31 observed, each equipped with polysomnographic recordings

and an electroencephalographic (EEG) to record brain activity. The subjects went to bed,

and various French words were played. They were expected to respond to classify the

words in certain categories using specific hand responses as long as they were awake,

even if they woke up in the middle of the night. However, a different list of words was

played based on when participants were in light, deep, or REM sleep. Based on the EEG
 THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 8

readings, the study concluded that during light sleep, the subjects' brains were still

classifying the words in their head. During deep or REM sleep, the subjects stopped

classifying the words but had increased brain activity (Andrillon et al., 2016). When

people wake up, they are more likely to be in the midst of light sleep, especially if they

are able to fulfill full cycles of sleep. The study’s conclusion shows that the brain is still

cognizant of sounds during light sleep but not in deep or REM sleep. This means that

when the brain hears the alarm during light sleep, it is able to signal to the body that it is

time to wake up, which can explain why alarms are an efficient way to wake up but also

why people struggle to wake up if they have not completed the ongoing sleep cycle.

Moreover, it is plausible to predict that heart rate may increase more if heard during light

sleep than deep and REM sleep, as the alarm is heard more suddenly and louder in light.

In an experiment conducted by the Inner Mongolia University of Technology,

they observed the impact of different types of alarm sounds and their impact on how

children perceive risk based on their psychological responses, as children may have

different reactions to alarms than adults due to their limited experience with danger. The

subjects were 42 kindergarten students split into groups of 14 based on ages (3 to

4-year-olds, 4 to 5-year-olds, and 5 to 6-year-olds). The experiment was announced to the

teachers but not the children. The students used an electrodermal sensor to measure

various variables, including heart rate variability. Three alarms were played: a voice

saying “fire, run” in Chinese, a classic fire alarm, and both played at the same time. The

alarms lasted until the students were out of the room and were played one after another

with a 10-minute cooldown period between each. The experiment concluded that each

alarm significantly shot the kids' heart rate up, but the type of alarm impacted how much.
 THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 9

The combined alarm showed the highest perceived risk from the children. The classic

alarm was second, and the voice alarm was last. This means the combined alarm showed

the highest heart rate increase, while the voice alarm showed the least (Zhou et al., 2019).

The experiment showed that each alarm varied in how much the children’s heart rate

increased; however, every alarm still caused a jump. This makes it conceivable to think

that hearing an alarm will definitely cause an increase in heart rate. Although the students

had the factor of potential danger, it is reasonable to think that hearing the sudden, loud

sound was the initial factor in the heart rate jump. Similarly, based on this experiment, it

can be concluded that an alarm with too many stimuli and or volume can increase heart

rate while having a classic, or better yet, a soothing alarm can lessen the impact, as it is

less jarring to abruptly hear.

Over the years, Apple has expanded its catalog of alarm ringtones. The ringtones

used in this study are called Radar, Signal, Sencha, Chalet, and Sunny. The first three

ringtones were released with iOS 4 back in 2010. According to a study, the best Apple

alarm ringtone to wake up to was Sencha, while the worst was Signal and Radar. Radar

also holds the title of being one of the most hated ringtones due to its loud and sterile

sound (Picken, 2022). In 2020, with the release of iOS 14, Apple introduced a new

feature to its phones and watches: Sleep Mode. Sleep Mode allows users to set up a

bunch of sleep-related features, such as new sleep-designed ringtones. One of those

ringtones is Sunny (Owen, 2020). Finally, in 2023, Apple released a whole new set of

ringtones with iOS 17, including Chalet. The ringtones have been hailed as being more

relaxing to the ear and well-received amongst Apple users (Peters, 2023).
THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 10

Summary:

Using an alarm utilizes and can impact many parts of the body. When a sound is

played, the ears will pick up the sound wave and transmit it to the brain to get processed

and added to a long catalog of recognizable sounds. Meanwhile, heart rate is the number

of times a heart contracts in one minute. A heart contracts due to blood moving into the

aorta, then through valves into the ventricles, and finally, through more valves into the

body. The ANS responds to sounds sent by the ears, and based on whether the heart rate

needs to increase or decrease, the PSNS or SNS will be in use. Even while asleep, the

body is still active and can process audio if collected during light sleep or a sound that the

brain is actively trying to identify. Related case studies show that the brain can process

audio better during light sleep, which is when the body begins waking up than in deep or

REM sleep, which shows why alarms are a successful way to wake up and that alarms

with too much stimuli or volume can increase the heart rate more than a simpler or

soothing sound.

Hypotheses:

Alternative: Radar and Signal will cause a person’s heart to increase, while

Sencha, Chalet, and Sunny will cause a person’s heart to decrease after listening

to the ringtones after a period of rest.

HA: P < 0.05 N = 18 (Radar)

HA: P < 0.05 N = 18 (Signal)

HA: P < 0.05 N = 18 (Sencha)

HA: P < 0.05 N = 18 (Chalet)

HA: P < 0.05 N = 18 (Sunny)

THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 11

Null: All of the Apple ringtones tested will cause a person’s heart rate to stay the

same after listening to one after a period of rest.

Ho: P ≥ 0.05 N = 18 (Radar)

Ho: P ≥ 0.05 N = 18 (Signal)

Ho: P ≥ 0.05 N = 18 (Sencha)

Ho: P ≥ 0.05 N = 18 (Chalet)

Ho: P ≥ 0.05 N = 18 (Sunny)

THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 12

Chapter III

Problem Statement: Which standard Apple alarm ringtone affects a person’s heart rate

the most after listening to one after a period of silent rest?

Methodology: A pulse oximeter will be used to measure the rate of heartbeats per minute

before and after an individual listens to a specific ringtone with their eyes closed. The

experiment will include 17 subjects.

Independent variable: Type of Ringtone (Radar, Sencha, Signal, Chalet, Sunny)

Dependent variable: Heartbeat Rate Per Minute (bpm)

Controlled variables: Duration of Alarm, Type of Headphones Used, Apple iPhone Used,

Volume Used.

Detailed Procedure:

The subject lies on a yoga mat placed on the floor in a quiet room. They are asked for

their name, age and whether or not they use an alarm to wake up. All responses were

recorded in the data table. The subject put on their headphones and closed their eyes to

simulate sleeping. Their resting heart rate was measured using a pulse oximeter and was

recorded in the data table. A minute later, the ringtone was played at the designated

volume for approximately 20 seconds. The participant’s highest heart rate after listening

was recorded in the data table. After a cooldown period occurred to get their heart rate

back to resting, the new resting rate was recorded and the other four alarms played in

using the same process. The whole experiment occurred 18 times.

THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 13

Data Information: The heart rates will be recorded with a pulse oximeter and the

various ringtones will be found on a standard Apple iPhone. A bar graph will be used to

see if there was a difference in the average heart rate of the subjects before and after

listening for each ringtone. Then, a TTEST will be used to see if there is statistical

significance.
 THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 14

Chapter IV

Subjects’ Heart Rates Before and After Listening to Ringtones

Ringtones
Radar Signal Sencha Chalet Sunny
Participants
Before After Before After Before After Before After Before After
*Heart Rate (beats per minute)
1 84 85 80 81 77 78 77 80 77 80
2 88 90 88 82 83 84 81 79 84 78
3 97 118 100 88 93 95 93 97 90 102
4 88 92 85 86 86 87 86 84 85 85
5 63 67 64 61 60 63 61 63 68 61
6 75 67 68 69 69 70 67 69 69 72
7 77 95 82 79 75 91 89 82 77 83
8 57 61 61 59 59 62 62 61 62 62
9 71 78 71 76 68 74 79 68 72 78
10 79 84 75 79 73 77 77 75 78 75
11 78 78 78 78 78 63 65 62 62 62
12 69 66 66 68 68 67 87 82 82 71
13 78 86 81 86 80 77 81 87 87 84
14 74 91 72 77 71 76 69 76 71 69
15 81 86 77 85 85 83 83 77 83 77
16 69 65 67 63 63 65 70 66 68 61
17 72 79 72 75 71 67 69 67 69 67
18 89 98 86 92 90 94 97 94 91 86
Averages 77.167 82.556 76.278 76.889 74.944 76.278 77.389 76.056 76.389 75.167

Standard Error 9.865 9.192 9.863 9.542 9.902 10.862 10.716 10.663 9.185 10.837

*Pulse Oximeter used has an uncertainty of +/- 2 BPM

THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 15

Statistical test results:

Ringtones Radar Signal Sencha Chalet Sunny

TTEST
Statistic 0.007514 0.607932 0.355124 0.240661 0.374321
(p-value)
THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 16

Chapter V

Introduction: Before analyzing the data, it is crucial to understand what the researcher

did precisely. The participants were asked to lie down on a yoga mat in a relatively quiet

area. As their heart rate relaxed, they were asked a few questions and to put the

headphones on. Then, five ringtones were played consecutively in the order of Radar,

Signal, Sencha, Chalet, and Sunny. The subject’s heart rate, before and after each

ringtone, was recorded and then averaged for analysis. Five TTESTs were run on the

data: one for each ringtone with their average heart rates before and after listening used.

Discussion and Critical Evaluation: After conducting the experiment, it can be

concluded that the alternative hypothesis for Radar, it will increase the heart rate, can be

accepted, while the null hypotheses, the heart rate will stay the same, for Signal, Sencha,

Chalet, and Sunny can be accepted. After the TTEST was performed for Radar, the

P-value equaled 0.007514, which is less than the critical value of 0.05; thus, Radar’s data

was statistically significant. This means that using the Radar ringtone may cause an

increase in a person’s heart rate when using it to wake up. However, the P-values for the

rest were greater than the critical value of 0.05, meaning that the data is statistically

insignificant. This means that the other ringtones keep a person’s heart rate around the

same when hearing them after a period of rest.

A majority of the collected data supported the null hypotheses of the ringtones.

This makes sense because, normally, when a person is in the process of waking up, they

are in the light sleep stage of sleep. During light sleep, a person’s brain is still active and

is able to process surrounding sounds (Mayer, 2023). If a person can maintain a

consistent circadian rhythm, the body’s 24-hour clock that dictates the sleep-wake cycle,
THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 17

they should be waking up at roughly the same time every day, and the body will naturally

be entering light sleep at that time (Suni & Singh, 2023). With light sleep and the

circadian rhythm, the brain will know when it is time for a person to wake up, and it has

time to prepare for a person’s wake-up alarm to play. As a result, a person is less likely to

be jolted awake by an alarm. Jolting awake would normally increase the heart rate since a

factor greatly impacting the heart is stress and shock, which can be caused by sound

(American Heart Association, 2023). However, the body’s natural processes have become

attuned to the sound to allow a more peaceful awakening. In addition, for the experiment,

the participants were just resting; they were not even in a state of sleep so they had

minimal, if any, shock only due to the noise being somewhat loud as regardless that

would impact the heart. Furthermore, the participants knew that an alarm would be

played and were expecting it. These weaknesses could have impacted the results causing

a lesser reaction. To fix them, each trial would need to be taken over a longer period of

time so the participants could have time to fall asleep and forget about the alarm; but,

with the constraints of this lab, that was not doable. Regardless, the results of this

experiment infer that the ringtones besides Radar tested will not cause the body to react

to being startled that much, which can be good for a person’s health in the long run.

For the unique case of Radar, it is plausible that the increase in heart rate can be

due to bias or the order in which the ringtones were heard. Radar is infamously known as

the “worst Apple ringtone” and called “so terrible” by many (Armstrong-López, 2022).

Apple, prior to iOS 17, had Radar set as the default alarm ringtone. This means that

anytime someone sets an alarm, unless they change the ringtone from the default, then

Radar is played. Over time, this can create a bias against Radar due to how loud and
THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 18

“unwelcoming” it is compared to other famed ringtones, causing the elevated heart rate.

A significant factor affecting heart rate is emotions. So, it is possible that due to the

negative emotions attached to the alarm caused the increase in heart rate (American Heart

Association, 2023). Even during this experiment, participants had a heavier emotional or

physical response to the alarm; for example, some people recoiled or groaned when it

was played. Likewise, a study about the best and worst iPhone alarms also found that

Radar was one of the worst alarm ringtones to use to wake up. It also found that Sencha

was one of the best (Picken, 2022). Both of these match the hypotheses that held true in

the experiment. It is important to note that a weakness of this experiment was that each

alarm was played in the same order. While it was necessary for the order to be held

constant so as not to alter each trial, Radar was played first every time. Being first meant

that the participants did not know when the first alarm was going to sound or how loud it

would be, increasing a person’s anxiety and heart rate. This could be an explanation for

why Radar’s data was statistically significant but not the other four ringtones. The alarms

could have been played on different days, one alarm per day, or the order of ringtones

could have been different with each participant to fix this issue.

The experiment also had a few other weaknesses. All of the participants, except

for two, said they used an alarm to wake up every morning. However, every person most

likely uses a different alarm with different volumes, frequencies, genres, etc. This could

mean that depending on the type of alarm a person uses, their heart rate may be more

used to or startled by each alarm in this experiment. The effect of this weakness could be

limited by asking each participant for their personal alarm ringtone and recording it in the

table for analysis. On top of that, the volume used to play each ringtone was slightly
THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 19

varied each time. For example, some of the ringtones themselves were louder than others.

This led to the researcher having to adjust the sounds to be approximately equal in

volume by ear. Moreover, the volumes for each ringtone in each trial were adjusted using

the volume buttons on the side of an iPhone or sliding a volume bar to approximately the

same area. The volume could have been adjusted using percentages rather than just

trusting the buttons or sliding to fix this problem.

In addition, there are a few limitations as well. First, some of the trials were

conducted using a different brand of pulse oximeters. Each brand differs a little bit in

their numbers and can cause a discrepancy between the numbers. Using the same pulse

oximeter for every trial would fix this issue. Next, the environment for each trial varied.

Some were taken in participants' homes, others in an empty classroom, and some in a

hallway. Each environment had slight differences in the number of people watching and

the regular background noise. Having as complete as possible silence was important for

the experiment, as the headphones were not noise canceling. To fix this, the testing room

should be the same every time, and as few people in the room as possible.

Closure: The implications of this study could be used to help scientists get a better

understanding of how to test the impact of noise on sleep. Through further study and

research, the true impact of alarms on heart rate can be found and help millions of people

get better sleep. Currently, after a complete night of silence, having an alarm break sleep

can leave people annoyed and groggy in the morning, leading to a bad start to the day.

Furthermore, the shocking noise of the alarm may increase the heart rate of individuals,

which can, over time, contribute to bad health effects in the future. Apple and other

brands will be able to use the data of all of these studies to create alarms that will be well
THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 20

suited for use in the morning and lower the heart rate of individuals to have them start

their day more relaxed. However, the statistically insignificant data may prove these ideas

wrong and that alarms are just a successful way of waking up in the morning, without

contributing to a person’s mood or health.

While the data in this experiment ranged from statistically significant to

insignificant, the data can be used by further researchers to get a headstart. Further

studies will be able to use this study to design a more significant method of studying the

impact and avoiding weaknesses. They should seek to have a more long-term study that

better mimics the night and morning experience.

THE EFFECT OF APPLE ALARM RINGTONES ON HEART RATE 21

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