That depends on what is NZ culture? Short answer is it’s many things, and deregulation has allowed for more of those things to reach the airwaves. Rather than having four BBC-esque stations in the cities and one or two in smaller towns (usually one which was semi commercial), we now have a clutter of voices and formats.
Some of the speech has represented NZ, but that was happening anyway by the 80’s. NZ broadcasters used to speak the Queen’s English on air, but since the 70’s-80’s this was already changing (look up Karyn Hay). I don’t think deregulation had much impact on that. But now as others have said, the American Twang has begun to creep in, but I have a feeling this may have more to do with the influence of YouTube. Does it represent NZ, no, it represent’s the USA.
You might find Audioculture useful as a launching point, either for some context on what was getting to air, or some of the contributors there might know someone who knows someone.
Look up NZ On Air for NZ music played on radio, they should publish percentages, etc. If not, ask them, I’m sure they’ll be happy to help.
The NZ Yearbooks give some context on what the NZBC were trying to do with Commercial Radio before deregulation. This comes from the 1961 edition; “The emphasis in commercial programmes is upon entertainment and, in addition to advertising matter which occupies a relatively small proportion of total broadcasting time, listeners may hear variety, dramatic, and comedy programmes of high standard as well as informative sessions, reviews, and a comprehensive announcements service.”
Television may have changed what kiwi’s expected.
For context, rather than to answer your question, you can look up old NZ Acts here, for any laws regarding radio (and broadcasting in general). Then again, was the point of deregulation to better represent NZ culture, or simply the Neo-liberal ethos which will always haunt the Fourth NZ Labour Party?
Try Brian FM for a different format. They’re slowly expanding where they can (RSM auctions off spectrum from time to time).
There are two major radio networks in NZ now, the former commercial arm of Radio NZ (NZME) and MediaWorks which is the result of the private stations over time have merging. Both specialise in music, but NZME have a sport station and another talk station. There are still some independent stations, like 1XX Whakatane, again, mostly music focused (but at least giving the locals a voice!). Most of the NZME and MediaWorks content is pumped down from Auckland.
Iwi (Maori) Radio operates in most centres, and of course there’s the state-funded Radio New Zealand (RNZ). Rhema run a couple of religious stations, the major centres have Chinese, Indian, and possible other ethnic-based stations. Student radio and an uncountable number of low-powered stations litter the airwaves with generally niche music where the bass is turned up far too loud. So I guess there’s plenty of content floating about…
Now to actually answer your questions…
Do Commercial Stations have anything that stands out as NZ? Not really. Brian FM taps into the style of kiwi humour with their adlibs, but I hear little of this on the other commerical stations. Local issues and politics are sometimes discussed, but often have very little depth or usefulness. Local disaster coverage can be patchy.
How often is NZ Music heard? Not enough and with not enough diversity either. More 40 Watt Banana please!
Does the Speech used Represent NZ? In some cases, but it’s eroding. Can we blame globalisation?
What makes NZ Stations unique?" Not a lot. Programming is much the same over the developed world, feed my the same commercial mechanisms to maximise profit.
Does NZ radio represent NZ culture and identity? Iwi Radio does, but where else are you going to hear Te Reo (the Maori launguage) being spoken? Otherwise, you might as well be listening to a radio broadcasting from anywhere.
And I’ll add this, I think only RNZ’s National station really tries to speak to NZers in their own voice, although pre-recorded programmes like Ted-talks have begun to seep in. But they’re not commercial, so exist beyond the scope of your dissertation. And perhaps that’s the reason why it’s still important for the Nation State to fund such things as non-commercial radio, in so that amidst creeping global noise, our own voice can still be heard. Even if were not still entirely sure what our own voice is (sounds like a thesis on identity there!)
Sorry if that’s all too wordy!