Feasibility on Detecting Door Slamming towards
Monitoring Early Signs of Domestic Violence
Osian Morgan
School of Computer Science and
Informatics, Cardiff University
Cardiff, UK
MorganOB@cardiff.ac.uk
Hakan Kayan
School of Computer Science and
Informatics, Cardiff University
Cardiff, UK
KayanH@cardiff.ac.uk
Charith Perera
School of Computer Science and
Informatics, Cardiff University
Cardiff, UK
PereraC@cardiff.ac.uk
Abstract—By using low-cost microcontrollers and TinyML, we
investigate the feasibility of detecting potential early warning
signs of domestic violence and other anti-social behaviors within
the home. We created a machine learning model to determine
if a door was closed aggressively by analyzing audio data and
feeding this into a convolutional neural network to classify the
sample. Under test conditions, with no background noise, an
accuracy of 88.89% was achieved, declining to 87.50% when
assorted background noises were mixed in at a relative volume
of 0.5 times that of the sample. The model is then deployed on
an Arduino Nano BLE 33 Sense attached to the door, and only
begins sampling once an acceleration greater than a predefined
threshold acceleration is detected. The predictions made by the
model can then be sent via BLE to another device, such as a
smartphone of Raspberry Pi.
Index Terms—Internet of Things, Anomaly Detection, On-
Device Audio Processing
I. INTRODUCTION AND MOTIVATION
With the ever-increasing availability of low-cost micro-
controllers and other computing devices, and advances in
more lightweight machine learning techniques, it is becoming
increasingly viable to make many of the everyday objects
found in our homes smarter. In this study we looked at the
feasibility of using inexpensive microcontrollers to leverage
machine learning techniques to detect specific phenomena. In
this case, we look at the possibility of using TinyML and an
Arduino Nano BLE 33 Sense to detect whether a door is being
slammed shut aggressively or being shut normally.
In a similar study [3], we see how the same Arduino board,
in conjunction with the Edge Impulse platform can be used to
detect the wing beats of Mosquitoes reasonably accurately.
The COVID-19 pandemic resulted in many changes and
restrictions for our daily lives, most notable being mandates to
work from home where possible, as well as legal requirements
to socially isolate. Between March 2020 and June 2020, police
in England and Wales recorded a 7% increase in offences
flagged as domestic abuse related, with the ONS noting a
general increase in demand for domestic abuse victim support
services (including a 65% increase in calls to the National
Domestic Abuse Helpline between April and June 2020,
compared to the previous quarter). Overall, the entire 12-
month period between March 2020 and March 2021 saw an
overall increase of 6% in domestic abuse related crimes. [5]
This follows general increases seen in previous years and could
be associated with increased reporting by victims, in addition
to improved recording by police forces. [1]
With this in mind, we seek to demonstrate the viability of
using microcontrollers embedded within doors in the home, to
assist social workers and law enforcement in the monitoring
of potentially aggressive behaviors and perhaps the early signs
of domestic violence in social housing.
II. OUR APPROACH AND METHODS
We began by breaking the problem down into its component
parts. Namely what physical properties can we measure to
determine if a door has been slammed, how do we decide if
a sample shows a slam or a normal close, and how could we
implement this in a way that’s practical for local authorities,
social workers and law enforcement?
A. How to quantify a closing door?
We decided that accelerometer and audio data were the most
useful for this task. When thinking about how a human would
decide if a door is being closed aggressively or not, there are
typically two physical parameters that spring to mind; how fast
the door is closing, and how much sound is generated when it
hits the frame. We then selected a suitable microcontroller for
the task, we opted for the Arduino Nano BLE 33 Sense, as this
small board ships with the required instruments as standard,
in addition to having BLE capability. Next, we experimentally
determined that a 2 second sampling window was sufficient
for slamming standardized MDF interior doors.
By recording variations in acceleration in three spatial
dimensions (x, y, z) we can see notable differences between a
slam and a normal close. We recorded this data using the IMU
on-board the Arduino and sent the samples to Edge Impulse, a
cloud-based web-platform for building and deploying machine
learning models for resource constrained devices, such as our
Arduino.
After collecting accelerometer data we moved on to collect-
ing audio samples, each sample once again being 2 seconds
in length. As shown in a 2021 study [4], we can see that
Arduinos are capable of handling audio analysis without the
need for a PC, thus keeping computing as close to the edge
as possible and allowing for their devices to be kept portable.
arXiv:2210.02642v1 [cs.SD] 6 Oct 2022