FOX start-up in existing CI recipients

Rationale

FOX is an ‘intelligent agent’, which means that it makes decisions based on artificial intelligence.  Since most of its knowledge is adopted from or generated in the Eargroup, the performance of FOX is best in the neighbourhood of the ‘local optimum’ of the Eargroup.  This means that MAPS that look like typical Eargroup MAPS will be treated more efficiently than other MAPS.  Hence, if existing CI recipients have MAPS that come close to the Eargroup style, FOX may treat them very efficiently.  If these MAPS however are very different from the Eargroup style, it may be more efficient to start from scratch with FOX’s Automaps.  We propose to make the distinction based on the performance on speech audiometry (phoneme score on monosyllable word lists).

Cut-off Criteria

We’ve looked at the distribution of the phoneme score at 70 dBSPL per SIR-category (Speech Intelligibility Rating).  If a long-term user has a higher score than P16 (median – 1 St.dev), then FOX may analyse this home MAP.  Else, it may be better to start from scratch.  Scratch then is the closest AutoMap that is lower than the patient’s home MAP.

It is important to use the category definitions exactly as defined here:

SIR

Definition

Cut-off phoneme

score at 70 dBSPL

0

Persons who have received an implant before the sixth anniversary

70%

1

Even the expert* hears no articulatory problems (articulatory problems attributed to non-auditory problems don’t count)

60%

2

The expert* may hear some minor problems (often /s/) which others may not even notice

55%

3

Everything between SIR 2 and 3: everybody hears articulatory problems, but they hardly impede good understanding

35%

4

The expert* may understand most of what the patient articulates, while others have huge difficulties

0%

5

Even the expert* has huge difficulties understanding the patient; conversation may require writing

0%

*Expert: audiologist or speech therapist who is used to work with hearing impaired persons

How strict is this?

Actually, these are merely guidelines and you are free to either FOX the patient’s home MAP or to start from scratch with Automaps.  Even if you prefer not to use the Automaps, Foxing the home map will generate interesting information for FOX to learn from.  But the trade-off may be that Fox may need several iterations to bring the patient from his/her current MAP to an optimized MAP.

Procedure

  • Score SIR
  • Perform speech audiometry @ 70 dB SPL
  • If score ≥ cut-off: add speech audiometry @ 40, 55 and 85 dB SPL, audiometry, loudness scaling and FOX the home MAP

    Else: Request AutoMaps è give the lowest AutoMap to the CI user and try to go to one or two higher AutoMaps è perform audiometry, loudness scaling and speech audiometry and FOX the AutoMap with this outcome