7/29/2019 Personal Computer-Based Audiometry

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Personal Computer-Based Audiometry

Wesley Jackson1 , Michael Merzenich 2

1. MIS is more accurate than our Bksy test comparedto the clinical audiometer.

Introduction

Conclusions

Compared to our Bksy test, the multiple-interval staircase test (MIS)

shows relative hearing loss that is significantly more similar to the loss mea-

sured by the clinical audiometer.

MIS is also significantly more reliable than our Bksy test.

Both online tests overestimate low-frequency hearing loss. We are cur-

rently investigating this bias.

Can you accurately and reliablymeasure someones hearing online?

We adapted the Bksy audiometer, a standard audiometric method, for

online measurement of hearing thresholds. However, complications in use-

ability and task learning motivated us to create a novel method.

We designed a novel, multiple-interval staircase method (MIS) to be more

engaging and ensure user consistency to correct for uncontrolled test envi-

ronments.

We compared the ability of these online tests to measure relative hearing

thresholds against a clinical audiometer and assessed their retest reliability.

Tones: pure tones spanning speech-frequency range (0.25-6kHz)

12 participants aged 21 to 71 took both online tests three times over three

days to assess test reliability. 5 of these participants were also assessed by a

clinical audiometer and were found to have hearing loss ranging from none to

severe. All participants were instructed to wear snug around-the-ear head-

phones and test in a quiet environment.

As these tests are not yet calibrated, they reveal hearing loss relative to the

users most sensitive hearing.

Results

No sounds are audible.

A. Bksy methodUser maintains loudness of tone sweep at minimum

audible level.

B. Multiple-Interval Staircase method (MIS).User selects all audible sounds of a given frequencyuntil a consistant minimum-amplitude threshold is found.

User selects all birds they can hear.

Some sounds are audible.

Are anyaudible?

YesNo

Adapt dBs to the threshold(quietest selected sound)

Increaseall amplitudes

by 30 dB

Isthreshold

consistent withlast time?

Current threshold is the absolutehearing threshold for this frequency

Yes

TEST NEWFREQUENCY

RETESTTHIS

FREQUENCY

Typical route forfinding threshold

No

STARTSet tone

dBs in 10 dBsteps

2. The novel method is more reliable.

Set tonedBs to 4 dB

steps aroundthreshold

Selected individual results above illustrate the dierence in relative hearing thresholds between the online tests andthe clinical audiometer. Individuals thresholds are relative to their most sensitive hearing (0 dB), though their actualhearing loss ranges from none to severe.

If you CAN hear the beeps,

HOLD DOWN the SPACEBAR!

If you CANT hear the beeps,

RELEASE the SPACEBAR!

Decrease amplitude Increase amplitude

Increase frequencyTime

Average dierence between relative hearing thresholdsfrom day 2 to 3. MIS has significantly less dierence

across retest(T1:m = 5.9,T2:m = 4.5,p< 0.01).

The frequency that could be heard at the lowest amplitude is an individuals most sensitive hearingthreshold (0 dB).

Negative dB values indicate how much louder the other frequecies had to be played to be heard,indicating relative hearing loss.

The dierence between the online tests and the clinical audiometer was determined by subtractingthe online test hearing thresholds from the relative thresholds obtained by the clinical audiometer.

How did we measure relative hearing loss?

Individal Results

limittime to respondbased on

playersaverage response time

limitnumberof timesplayercan reviewastimulus

Overestimated

Loss

UnderestimatedLoss

Average dierence of online tests from theclinical audiometric relative hearing t hresholds.

MIS is significantly more accurate thanour Bksy test (T1:m = 9.2,T2:m = 6.2,p< 0.05).

*

Both tests overestimate low-frequency hearing loss , but ourBksy test also underestimates high frequency loss.

This dierence is significant (p< 0.05).Online test bias is highlycorrelated with frequency(T1: r= -0.75,p< 0.05;T2: r= -0.85,p < 0.01).

* p< 0.05

Dierence Between Online Tests and Clinical Audiometer

**

** p< 0.01

BestHearing

Worst

Hearing

Methods