New Zealand’s one-implant policy for adults was designed to make limited funding reach more people. That remains a real constraint. But the evidence for a second cochlear implant is stronger than it was when the rule was set.
New Zealand’s published funding rules draw a firm line. Children under 19 with severe-to-profound hearing loss in both ears may receive one or two publicly funded cochlear implants when clinically recommended. Most adults receive one. The main exception is an adult who has had meningitis and is at risk of cochlear ossification.
The Government’s reason is straightforward: funding is limited, and providing one implant per adult allows more people to receive a first implant. That is not an irrational policy. It is an attempt to distribute a scarce health service fairly. (Disability Support Services)
But a funding rule is not the same as a clinical endpoint. The question is no longer whether one cochlear implant is useful. It plainly is. The question is whether New Zealand should continue treating the second ear as an optional extra, available mainly to adults who can find around $50,000 themselves.
What does a second cochlear implant add?
We have two ears for a reason. The brain compares sound arriving from each side to work out where it is coming from, separate speech from competing noise and maintain access to a voice when a person turns their head or a speaker moves.
A first cochlear implant generally provides the largest gain. It can restore access to speech where hearing aids no longer provide enough information. A second implant does not double that benefit, create normal hearing or guarantee the same result for every recipient. What it can add are some of the functions that depend on receiving sound from both sides.
A 2025 systematic review and meta-analysis examined 35 studies comparing bilateral and unilateral cochlear implants in adults. On average, bilateral users recorded a 12.6 percentage-point improvement in speech perception in quiet and a 1.5 decibel improvement in the signal-to-noise ratio needed to understand speech. The review also found better sound localisation and improvements in hearing-specific quality of life. Generic quality-of-life scores were mostly unchanged, and the researchers noted considerable variation between studies. (PubMed)
Those findings build on a Dutch multicentre randomised clinical trial. Adults who received two implants performed better in demanding listening situations, particularly when speech and noise came from different directions. Benefits in spatial hearing remained evident at the two-year follow-up. (Maastricht University)
The qualifications matter. Group averages do not predict an individual result. The two implanted ears may perform very differently, particularly after a long period without useful hearing in one ear. A small 2022 study of 12 bilateral users found no average speech advantage in quiet over the better-performing implant and no consistent reduction in listening effort. For some adults who retain useful acoustic hearing, one cochlear implant combined with a well-fitted hearing aid may remain the better two-ear solution. (Frontiers)
The evidence therefore supports access to two-ear hearing, not two implants for every adult regardless of circumstance.
What adult users report
Clinical tests measure speech scores, decibels and localisation errors. They do not always capture what it means to chair a meeting, follow several people around a dinner table, hear a colleague from the other side of a room or stop relying on a partner to interpret every phone call.
South Taranaki farmer Richard Milne’s experience, previously shared by Pindrop, illustrates the point. As his hearing deteriorated, Richard relied on his wife, Lynne, during business discussions and for phone messages. Social outings became so difficult that the couple largely stopped going out. Richard privately funded his first cochlear implant in 2018 and then a second. He reported gaining directional hearing, greater confidence using the phone and an increased ability to speak with people without requiring Lynne to manage the exchange. (Pindrop Foundation)
One person’s account is not a clinical trial or an economic evaluation. It does, however, identify costs that conventional hearing tests can miss: dependence on another person, withdrawal from ordinary situations, reduced professional autonomy and the work done by family members to compensate for one-sided hearing.
That distinction is important. Public policy should not be based on testimonials alone. Nor should it dismiss real-world functioning because it is harder to enter into a spreadsheet.
Are two cochlear implants cost-effective?
This is where the case becomes more complicated.
Under a fixed budget, funding a second implant for one adult may mean delaying a first implant for somebody else. Because the first implant commonly delivers the larger gain, a public health system cannot simply assume that two must always be better value than one.
Pindrop currently gives an indicative private cost of about NZ$50,000 for a second implant, including the device, surgery and rehabilitation. Adults who pay privately must also plan for maintenance, replacement parts and future processor upgrades. That figure is useful for understanding the burden placed on individuals, but it is not necessarily what a national health service would pay through negotiated procurement. (Pindrop Foundation)
The economic research does not produce one universal answer. A 2024 systematic review concluded that unilateral and sequential bilateral cochlear implantation appeared cost-effective compared with hearing aids or non-technological support. It also found that simultaneous bilateral implantation could become cost-effective under particular assumptions, including device discounts and sufficient life expectancy. The authors warned that differences in comparators and modelling methods affected the results. (PubMed)
A separate 2024 European review found wide variation between countries in costs, health-system structures, time horizons and the monetary threshold used to define value. Some models found bilateral implantation became cost-effective over longer periods, but the result was heavily influenced by the price of the second device and the number of years over which benefits accumulated. The review’s central conclusion was that countries need analyses based on their own health systems and costs. (Springer)
One economic analysis attached to the Dutch randomised trial found that a second implant became cost-effective after five to 10 years using several hearing-related utility measures. It involved only 38 adults, used European costs and took a health-insurance perspective, so it cannot simply be transferred to New Zealand. It does show why a short budget horizon can produce a different answer from a lifetime analysis. (PubMed)
The experience of England’s National Institute for Health and Care Excellence, or NICE, also demonstrates how much procurement matters. NICE currently recommends bilateral implants for children and for a limited group of adults with other disabilities that make them especially reliant on hearing for spatial awareness. Its adult bilateral economic conclusion dates from 2009. In that model, discounts of 25% and 50% on the second implant substantially reduced the cost per quality-adjusted life year, although not enough for NICE to recommend routine bilateral adult implantation. NICE requires discounts equivalent to at least 40% on a second device where bilateral implantation is funded. (NICE)
The lesson for New Zealand is not that an old British calculation should determine our policy. It is that the price of the second implant is negotiable, and procurement strategy can change the economic result.
The taxpayer return is wider than a hearing test
Cochlear implants affect employment, participation and the amount of support people require from others. A 2023 systematic review of adult cochlear implantation found that 27 of the 35 studies examining social outcomes reported improvement in at least one area. Positive findings included employment, social participation and autonomy. However, the review covered cochlear implantation generally—not the additional effect of a second implant—and none of the included studies had a low risk of bias. (Springer)
That is both encouraging and limiting. Evidence that cochlear implants improve working and social lives cannot all be credited to the second ear. New Zealand needs to measure the incremental difference between one optimised implant, an implant plus hearing aid, and two implants.
The wider economic context still matters. An NZIER report commissioned by the New Zealand Hearing Industry Association modelled potential annual GDP gains of between $718 million and $924 million if hearing-related absenteeism and reduced productivity were mitigated across the working-age population. This was a model of hearing loss generally, not a business case for bilateral implants. It nevertheless shows why an assessment confined to surgical costs and generic health scores will be incomplete. (NZIER)
A credible New Zealand evaluation should therefore count health-system expenditure, processor and rehabilitation costs, employment, sick leave, continued workforce participation, dependence on family members and hearing-specific quality of life. It should not assume that every benefit will occur, but it should not value work and independence at zero.
Children receive two. Should adults?
There are strong reasons to fund bilateral implants early in childhood. Access to sound from both sides can affect speech and language development, education and the formation of auditory pathways. Those benefits may accumulate across an entire lifetime. Adults who have already developed language are not clinically or economically identical to children. (NICE)
That difference justifies distinct assessment criteria. It does not justify assuming that two-ear hearing stops being relevant on a person’s nineteenth birthday.
A young adult may have 40 or 50 years of employment ahead. An older adult may still work, care for other people, volunteer, manage a household and need to communicate in complex medical settings. Age can influence likely benefit, but an age boundary alone is a crude substitute for clinical assessment.
Recent clinicians and ethicists writing about bilateral cochlear implantation have argued that the goal should be the best achievable result across both ears. For some people that will mean two implants; for others it will mean an implant and an acoustic hearing aid. Their argument is persuasive because it moves the decision away from a blanket rule and towards the additional value a second implant is expected to provide. (BMJ Blogs)
A realistic funding model for New Zealand
The choice is not between immediately funding two implants for every adult and maintaining the current rule forever. New Zealand could introduce a staged, targeted entitlement.
First, protect access to a first implant. Funding for second implants should be additional and ring-fenced. It should not be created by reducing the number of adults receiving their first cochlear implant or extending their wait.
Second, use clinical selection rather than automatic eligibility. Adults should be considered where both ears have severe-to-profound loss, the first implant has been appropriately programmed and used, and an optimised hearing aid in the other ear provides insufficient functional benefit. Assessment should consider speech in noise, localisation, duration of auditory deprivation, residual hearing, balance function, work and communication requirements, and the person’s capacity to complete rehabilitation. There should be pathways for simultaneous implantation in appropriate new candidates and sequential implantation for existing users.
Third, negotiate the second-ear cost as a separate price. A national contract should seek substantial second-device discounts and account for lower duplicated costs when two implants are placed during one surgical episode. The package must include rehabilitation, maintenance and future processor provision; otherwise, the public system merely transfers ongoing costs back to the recipient.
Fourth, measure the result in New Zealand. A staged national programme should collect speech-in-noise and localisation results alongside hearing-specific quality of life, listening effort, work participation, support required from whānau, adverse events and lifetime service costs. Outcomes should be reported by age, region, ethnicity and whether implantation was simultaneous or sequential.
Equity must be built into the policy from the start. A 2025 review of referrals to the Southern Cochlear Implant Programme found that geographic access had improved, but Māori and Pacific people appeared to remain under-represented, with incomplete ethnicity data limiting firm conclusions. Expanding second-ear funding without addressing referral inequities could disproportionately benefit people who already know how to navigate the system. (The New Zealand Medical Journal)
Pindrop’s position
Adults should be eligible for two publicly funded cochlear implants when a multidisciplinary assessment finds that the second implant is likely to provide meaningful benefit beyond one implant or an implant combined with a hearing aid.
That does not mean two implants on demand. It does not mean ignoring surgical considerations, residual hearing, rehabilitation or the variability in results. It cannot mean taking a first implant away from another adult.
It means accepting that the evidence has moved beyond the assumption that one implant is always an adequate endpoint. It means negotiating harder on price, measuring the outcomes that matter in daily life and giving adults a fair clinical assessment rather than an automatic refusal.
Public health systems deal in opportunity cost. The responsible position is therefore neither “two for everyone” nor “one forever”. It is a separately funded, clinically targeted bilateral pathway with transparent criteria and New Zealand data.
Two ears do not become a private luxury at 19.
