Kalpit%20V.%20Desai

1
SoundMaker Physics-Based Synthesis of Car Sounds

• Kalpit V. Desai
• kvdesai_at_email.unc.edu

2
Overview

• Synopsis
• Motivation
• Overall Approach
• Detailed Model
• Demo

3
Synopsis

• Synthesize sounds of a car
• Target application Street-Crossing Simulator
• other applications Setting noise standards,
  Games etc.
• Goal to develop a parametric model based
  entirely on principles of physics
• Use of signal processing concepts
• Why not use recorded sounds?

4
Motivation

• Recorded sounds
• Noise or extraneous inputs in recordings
• Inefficient for real-time control
• Limited applicability
• Parametric model
• Versatile
• change in value of parameter a new car
• Efficient for use in real-time

5
Overall Approach
C/S Area
Wind

Stereo Output

Doppler
Enginemuffler
Velocity

Acceleration (throttle)
RPM
Weight
Tyres
6
Detailed Model Engine 4 strokes
7
Detailed Model Engine (Cont)
Remove Frequencies gt20K
Output Sounds
RPM
Muffler
Engine One Cycle
8
Model Wind Tyres

• Wind Friction
• Band Limited White Noise (negligible at very low
  frequencies)
• Amplitude proportional to square of velocity
• Amplitude proportional to cross-section of
  vehicle
• Tyres
• Band limited pink noise (HF prop. to velocity)
• Amplitude proportional to weight

9
Doppler Effect
10
Demo

• (urrsort of ?)

11
Future Plans (before GrandET demo)

• Solve the puzzle of muffler model
• Add Doppler effect
• Replace Matlab script with interactive GUI

12
Questions?
Thank You!