Individual DPOAE Level Map Fitting for Faster Threshold Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for determining distortion product otoacoustic emissions (DPOAE) thresholds in hearing assessments suffer from high standard deviations and measurement errors due to interference between source contributions and individual variations in optimal excitation levels, leading to inaccurate estimations and prolonged measurement times.

Innovation Solution

A method for automatically determining an individual DPOAE level map using predefined excitation level pairs and pulsed DPOAEs to suppress interference, allowing for the acquisition of additional data on frequency resolution and sound transmission loss, while minimizing estimation errors by sampling the level map along a linearly rising ridge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional DPOAE threshold measurement methods are used, then the measurement process is simple, but the measurement precision is poor due to high standard deviation and interference from source contributions

Engineering Contradiction:
ImproveDPOAE threshold determination accuracyVSAvoidmeasurement process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the DPOAE measurement process into multiple frequency pairs (e.g., 5-7 frequency pairs instead of a single frequency), allowing the system to capture the growth function across different frequencies. This segmentation enables more accurate threshold determination by averaging results across multiple measurements, reducing the impact of interference from source contributions while maintaining a manageable measurement workflow.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an automated computer-based system that acts as an intermediary between the stimulus presentation and threshold determination. This system automatically presents multiple frequency pairs, records DPOAE responses, fits growth functions, and calculates thresholds, thereby reducing manual intervention and minimizing errors from subjective judgment while improving measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If optimal excitation levels are determined individually for each subject, then the measurement accuracy improves, but the measurement time increases significantly

Engineering Contradiction:
ImproveDPOAE measurement accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements preliminary action by automatically presenting multiple frequency pairs with predetermined level combinations before final threshold determination. The system pre-defines excitation levels (e.g., L1=65 dB SPL, L2=55 dB SPL) and presents them across multiple frequency pairs to establish the growth function, thereby capturing individual variations without requiring time-consuming manual optimization of each subject's excitation levels.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes parameters by systematically varying frequency pairs (e.g., 1000/1200 Hz, 1500/1800 Hz, 2000/2400 Hz) and excitation levels across multiple measurements. This parameter variation allows the system to identify individual growth function characteristics and determine optimal excitation levels automatically, achieving both accuracy and efficiency by capturing individual variations through automated parameter sweeping rather than manual optimization.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If multiple frequency pairs are measured to reduce interference effects, then the measurement reliability improves, but the quantity of measurements and processing complexity increases

Engineering Contradiction:
ImproveDPOAE threshold measurement reliabilityVSAvoidmeasurement efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges multiple frequency pair measurements into a single integrated analysis. By presenting 5-7 frequency pairs and fitting a growth function to all responses simultaneously, the system combines the information from multiple measurements to produce a single reliable threshold estimate. This merging approach maintains high reliability through multiple measurements while improving productivity by automating the integration and analysis process, avoiding the need for separate manual evaluations of each frequency pair.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method provides accurate, rapid determination of DPOAE thresholds and slope of the growth function, reducing measurement time and eliminating estimation errors, thereby improving diagnostic accuracy and efficiency.

Implementation Method 1

The nonlinear characteristic of the mechanoelectric transduction of the ion channels of the outer hair cells, which constitute the main motor element of the cochlear amplifier in humans and mammals in general, leads to numerous distortion products.

Methodology Applied
Scientific EffectNonlinear mechanoelectric transduction:

Implementation Method 2

These are sounds generated as a byproduct by the active amplifier and transmitted backward through the middle ear to the ear canal. There, they can be measured with sensitive miniature microphones.

Methodology Applied
Scientific EffectOtoacoustic emissions: Acoustic Emission

Data Source

PatentEP3429457B1Method for automatically determining an individual function of a dpoae level map of human or animal hearing
Publication Date: 2026.05.13 EBERHARD KARLS UNIVERSITAET TUEBINGEN
  • EP3429457B1 patent drawingFigure 1
  • EP3429457B1 patent drawingFigure 2
  • EP3429457B1 patent drawingFigure 3

AI summary

A method for automatically determining an individual function of a DPOAE level map of human or animal hearing includes the following steps: - reading a model function p dp,M = f( L 1 , L 2) with model parameters of a DPOAE level map on the basis of a number of N DPOAE measurements of an excitation frequency pair f 1, f 2 with respective different level pairs {L 1 (1.. N ), L 2 (1.. N )} in a population of normal hearing subjects, - presenting n different level pairs {L 1 (1..n), L 2 (1..n)} of an excitation frequency pair f 1,f 2 via audio output means (21, 22) to an individual and detecting the DPOAE of the individual via audio capturing means (23), wherein at least the first level pair {L 1 (1), L 2 (1)} is defined, and n « N, - iteratively adapting the model function p dp,M to the measured n DPOAE until an individual function p dp,I = f( L 1 , L 2) is obtained with individual parameters of a DPOAE level map of the individual, and - outputting the individual function p dp,I .