1. Requirements

• Understand variations in the audio spectrum caused by hardware, software frameworks, and marketing emphasis.

• Solve problems discovered through internal post-mortems and user data analysis.
   

2. Problem Definition

• Why should sound be part of the product’s UI?

• What specific problems can sound design solve?

  Example

• Are there feedback signals that cannot be perceived through standard touch or click interactions?

• Are there scenarios (e.g., in motion, during exercise, while playing other media) where users cannot easily check visual feedback?
   

3. Hypothesis Building

• Formulate hypotheses on how sound design can address the identified problems.

  Examples

• Smartwatch users will reduce screen-checking while cycling by X% when sound feedback is available.

• Users who set sound feedback only for critical actions will check their smartphones less than X times during a movie.

• Providing an OFF sound will reduce unnecessary double-checking of power status by X%.
   

4. Design Planning
Develop methods to translate product design and visual concepts into sound.

• Reference & Sketch: Create references, sketches, and internal sharing guides

• Prototype Development: Build prototypes for stakeholders and user testing

• Detailed Design: Validate synthesis, instrumentation, and collaborate with artists, orchestras, and voice actors
   

4-1. Analysis

• Review overarching principles and product context

• Prioritize data-driven approaches to prevent unproductive debates
   

4-2. Target User Definition

• Who are the target users?

• Consider special user groups (hearing-impaired, audio-dependent) alongside general users
   

4-3. Emotional Perspective

• Define tones/frequencies that may trigger negative emotions

• Distinguish between used vs. preferred instruments

• Measure volume ranges affecting arousal

• Establish a Mood Quadrant based on genre, scale, and chord
   

4-4. Functional Perspective

• Are pitch levels appropriate for the device environment?

• Do feedback sounds follow consistent grammar (positive/negative, connect/disconnect)?

• Is sound feedback truly necessary?

• Could redundant feedback confuse or mislead users?
   

4-5. Branding Perspective

• Design sounds recognizable as brand identity

• Use musical grammar for clear user feedback

• Establish long-term cross-category principles (smartphones, cars, appliances, IoT)
   

4-6. Consistency as a Design Element

• Align with graphic/interaction UI themes

• Match CMF and product design concepts

• Reflect marketing messages and brand voice

• Consider strategic use of sound across products
   

5. User Research

• Select target users by region, gender, group

• Test prototypes for problem-solving ability and hypothesis validation

• Include accessibility testing for users with disabilities

Example Items

• Do visual and auditory elements align?

• Do emotional expressions match?

• Which sound is most preferred?

• How do responses differ when varying levels at the same frequency?
   

6. Iteration

• Repeat process if hypotheses remain unproven or new variables emerge

• Carry unresolved issues into backlog or next sprint planning
   

7. Design Handoff

• Agree on file formats with development team

• Plan designer participation in dynamic sound design (e.g., FMOD)

• Test in multiple listening environments, including anechoic chambers

Checklist

• Measure max/min/default decibel levels

• Check for speaker noise

• Tune speaker type and chipset for optimization
   

8. Product Launch

• Analyze PR materials and regional user reactions

• Apply updates for improvements

• Collect post-mortem data for iterative enhancements