Listening to TV conversations is a high bar. In conversations people can ask for clarification or to slow down etc.

Which explains: Before implantation, 7% of the patients were able to have telephone conversations. vs After implantation, 60% of patients are able to have telephone conversations.

Also, the technology dramatically improved over time so we don’t have long term data on high quality implants.

Still, pay attention to context. This was people who were successfully using hearing aids and oral language before implantation. Even in this subpopulation, they did not do nearly as well as children do, even though this subpopulation was less deafened than most deaf children.

> Also, the technology dramatically improved over time so we don’t have long term data on high quality implants.

We do have enough series to know that 5 year olds receiving treatment have (on average) significantly worse outcomes than 18-24mos.

For the timescales we have tested there’s significant differences, and in terms of quality of life it’s clear early intervention is a significant benefit.

However, slower adaptation isn’t zero adaptation. The limits for people implanted at 5 when they are 50 is still an open and IMO interesting question.

> The limits for people implanted at 5 when they are 50 is still an open and IMO interesting question.

Slower development usually means a lower plateau, and I think we pretty much have to assume as such (and can be prepared to be pleasantly surprised).

Else, we get to wishful thinking: older people on older devices developed more slowly and plateaued at a lesser value of hearing. Now, we have implanted older people on newer devices, and they're developing more slowly, but hey, maybe they'll eventually develop fully normal hearing.

Do you have a source for that plateau? I’ve read that early success predicts future success on age adjusted tests. But the children were still improving in absolute terms over a decade post surgery.

I was arguing mostly from the standpoint of delays in development are almost always correlated with lower ultimate attainment, no matter what measure you're looking at.

But if you want cochlear implant specific data, here-- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10760633/

You're right that time narrows the gap between early implantation and later implantation, but the slope of that narrowing is pretty small by the 20 year mark (and barely statistically significant in this moderately-sized study) and the gap is relatively big.

The difference of time of implantation between the two groups was relatively small (mean implantation at 45 months vs. 34 months) and produces a gap that's durable for decades. >130 months is way, way, out from 45 months.

Very interesting paper!

Still, lots of work to do, to quote "However, it was not possible to control other factors, such as the socio-economic environment of the participants.".

In my view this could affect the study quite a lot (or not, but unknown for now). They mention the initial intervention was 3 months on-site, but after "the patient returned to his area of residence, where he/she would have speech therapy and special education".

Thank you, interesting read.

Looks like scores are still improving at 25 vs 20 years. Though excluding tests which maxing out the gaps never closed.

I was surprised at the amount of continuing improvement, too.

Never fully catching up sounds a lot different than "window for learning spoken language is permanently shut". Am I missing something?

"Permanently shut" for everyone is probably an exaggeration.

A better description "very, very few of those [with hearing restored] after age 5, who had never had any hearing before, develop anything close to normal spoken language skills."