By popular demand, #SOVT expert Oren Boder, creator of the SOVT Singing Straw, is back!
We had so many more AMAs for Oren following our SOVT Workshop together that we invited him back for SOVT AMAs part 2 (part 1).
In part 1 of this two-part return, Oren, Gillyanne and Jeremy answer questions on:
You can get Oren's brilliant metal straw (we highly recommend it) from https://www.sovtstraw.com/?ref=VOCALPROCESS - use the code Vocalprocess to get 15% off your shiny new straw
You can learn more about SOVT techniques on Oren's online (hands-off) course here https://www.ob1.co.uk/sovt.html?ref=VOCALPROCESS (10% off with the code VocalProcess)
Or join Oren, Gillyanne and Jeremy for a repeat of the LIVE online SOVT workshop here https://store.vocalprocess.co.uk/sovt-workshop
Watch Jeremy and Gillyanne use the straw when they coach Musical Theatre vocal and performance techniques https://www.ob1.co.uk/mmt.html?ref=VOCALPROCESS
This is a voice, a podcast with Dr. Gillyanne Kayes and Jeremy Fisher.
Hello, and welcome to podcast 13. And he's back. We have so many questions about SOVT. And we should say that Oren Boder, who's our guest today, Gillyanne and I did a course last Saturday, which was the SOVT workshop, which was actually amazing.
Gillyanne Kayes 0:39
And we have had a barrel load of questions, which we decided to make this podcast the SOVT AMA part two.
Gillyanne Kayes 0:48
So thank you, first of all, Oren you were our first podcast guests. And you're also another first is that you've been our first pop up workshop guest as well.
So welcome to the podcast. And we have we're gonna go straight in. We have so much Oh, no, you've got a thing.
Gillyanne Kayes 1:07
You haven't given him a chance to speak yet. Can I just give you some feedback? Which is about the course. "Thank you so much for arranging, arranging that. So many things to go away and work on. Despite the rain, I bounced back into the house, and gushed a load of things at the husband, he now looks shell shocked and doesn't really understand anything I've just said." I think that's good feedback
We'd like to give a personal apology to Grace's husband. Great, hello, how are you?
Yeah, hello. Good. Actually, I'm still kind of buzzing from the other day. It was really fun. Yeah. And I think the the types of questions, the types of ideas that everybody was having, is going to be so cool and interesting to discuss today. Yes.
Gillyanne Kayes 2:03
I think you know what, I was, I've been thinking about it, obviously, since Saturday. And although there is scientific research, and also quite a lot of theoretical research into how SOVT works, we're really only at the beginning of what it means to put it into practice in different situations. In singing, teaching, and voice use, we know something about therapeutic voice work. But we don't know a lot about purposing it in singing, teaching. So I feel in a way that the course that you've created and what you're doing is really contributing to that and that we need an army of people out there now to sort of go out, try things out and start collating that info, which for me as a researcher is hugely exciting. Okay.
So we have people have been submitting questions in all sorts of ways. We have questions on email, we've had them on Facebook, and we've had some of our speakpipe.com/VocalProcess people have been using that which means we actually get to hear their voices and we got four or five of those. So I want to go straight to...
Gillyanne Kayes 3:10
Should we ask Oren first to do a very quick definition of what SOVT is, what we mean by that?
Okay, you got 30 seconds, go.
Okay. SOVT, so semi occluded vocal tract basically means that there is some kind of partial occlusion, partial closure at any point along the vocal tract above the vocal folds. That partial closure creates really cool little physics tricks and interactions that sends air pressure and acoustic energy backwards to re interact with the vocal folds. Basically, we're just recycling all of the energies that we've outputted so we can reuse that for our benefit when doing other singing tasks
Gillyanne Kayes 3:55
It's like regenerative braking
great, it IS like regenerative breaking we've just got a new EV and I am loving, regenerative brakes so
Gillyanne Kayes 4:05
It makes so much sense. Yes. So much sense that you are there's a new is it that one was an analogy for you, in addition to your soft-close cupboards. Yes.
We'll come to the soft-close cupboards in a minute.
Gillyanne Kayes 4:18
We will indeed.
So technically, pretty much anything above the vocal folds can be an SOVT device. So it could be the back of the tongue, it could be the lips, it could be the soft palate, it could be anything. And where we're looking at now is the difference between active and passive SOVT. So talk to us about that.
Yeah, so um, it's probably easier to explain the passive stuff first. So passive is just by using some kind of device or tube or straw that is independent from the body that you placed at the level of the lips. And so you haven't really got to do anything physical except for just gently sealing the lips around whatever it is you're using. Active then is kind of one of those things that you've just kind of explored there. It's the other stuff that you can physically manually manipulate about your anatomy and articulators and all that kind of stuff.
Gillyanne Kayes 5:12
Yes. Yeah. And I think one of the neat things you said in the workshop was that, in fact, it's easier for us to control the passive form the sort of the variables there. Because we don't always get you know, enough biomechanical feedback about what we're doing internally.
Yeah, exactly. And it's also more reliable to use something like passive because you could always come back to and use the same length or diameter or whatever, of straw. Whereas when you try and reposition the things that you do actively, you know, you might have a slightly different tongue position or slight different mouth shape. So it's harder to be more reliable with the effects that you want to receive.
Yes, okay. Yeah, absolutely.
Gillyanne Kayes 5:57
All right. Well, I've been using straws empirically for, ooh I don't know about three or four years. And I'm sure lots of other singing teachers have been doing so as well. And I hope that these questions that are coming up are going to help with understanding and giving people ideas.
So I'm going to start with Monia, Monia de Swart said my biggest question is how to get my students from straw work to actual singing, even with the humming and singing the melody with the straw it still seems such a big gap when articulation comes in. And in fact, she was not the only person to ask that
Gillyanne Kayes 6:33
We had something similar from Franka on Speakpipe
From Franka, in fact let me play Franka's, because because it's very similar.
My first question would be how to go from straw phonation, either in water or not to actual singing? And what happens with the effort? Because when you go back to normal singing, there is more effort needed?
We might have to unpack that from Franka. But what's what's interesting is the basic question is how do you go from straw phonation to singing? Well, let's start with how do you go from straw phonation to singing vowels?
Gillyanne Kayes 7:12
Okay, so do you want to start Oren? Because we've got thoughts as well, obviously.
Yeah. So I think what I would do is, work with straws, and then begin to interchange between straw work, vowel work straw work vowel work, straw work, vowel work. And so you kind of put put the normal stuff in the middle of where of the straws. And so you kind of create that environment, then you do the work without the straw with that environment. Still persistent. You bring the straw in. I would initially start with that. I think that I think there's a lot of other things to bring into it. I have a feeling. Jeremy, you might have some different... differences there. Yeah, it'll be interesting.
No, not at all. No, I think what you're talking about is comparison. And I think comparison is absolutely vital. Yeah, we do a lot of exercises where we go from speaking setup to singing setup, and singing setup to speaking setup, because you're doing comparison all the time. And I'm thinking when you're doing, I want to break this down really finely. Let's say that you have a particular phrase that you want to sing in a song. And we're taking the straw phonation now away from warm ups, and we're putting them into actual practice.
So the first thing that you do is you have done a warm up with the straw, or you've been working with the straw just over your range generally, to get the balance that you want, just into in a sort of general balance terms. Then you sing the, well, you see I hesitate to use the word hum.
We had this conversation, I hesitate to use the word hum because hum normally means a nasal consonant,
Gillyanne Kayes 8:59
You vocalise into the straw.
Thank you. So just just to break that down. Sometimes if you hum, you will most certainly hum on a nasal consonant, which means the door into the nose is open. And you don't want that when you're doing straw work because it will bifurcate the air flow, and you don't want that you want all the air coming down the straw. Okay, so you, phonate down the straw at pitch. You sing down the straw
Gillyanne Kayes 9:25
In your target phrase
In the target phrase and what you're listening for / feeling is a balance in that particular phrase. You then take the straw out and reproduce the feeling, the balance, the volume without the straw, and then you go put the straw back in and do the same thing. Take it out and do the same thing. Now we're on vowels at the moment. It's it can be a single vowel on a phrase like that, so that you have a really direct comparison. That's how I go about with vowels and we'll talk about consonants later
Gillyanne Kayes 9:58
Yes and I think As a teacher as well, in between, if I was introducing the technique to a student, I would be saying, does it feel different as you move from singing the song in your normal way to singing through the straw, to singing with the straw, and then into vowels, what feels different. So to get the student to articulate that difference, in their own words, so they can start to reproduce that it is a kind of reprogramming. And I think the contrast and compare phase, which, frankly, is something we do all the time teaching anyway, as Jeremy said, I think that's the empirical bit that the teacher has got to be prepared to do. And to notice, you know, if this if the student says, actually, that feels harder, or it feels tight down here, that might be a time when you actually change the width of the straw, but I'm sure we'll come up to that later.
I think following from that, as well. Jeremy, I know we had a conversation the other day about potentially creating the shapings of the vowel sounds, whilst keeping the straw in place. Obviously, you're kind of mitigating the the effects of how the mouth is going to articulate things, but I think you can get a very good representation. And potentially that is another good way to go, is to really just try and train those shapings whilst having the efficiency of the straw. I would maybe even consider that as a precursor to the comparison phase, that's like an extra layer.
Yeah, yeah, I like that
Gillyanne Kayes 11:31
Do you know, I haven't tried that myself. So that's going to be in my next session.
There's something I want to pick up. Because what we're suggesting is that you do it from the straw to the singing and not from your standard singing to the straw. Because there's a question that's coming up. And it's actually Franka's third question. She submitted three, where we we talked about that a little bit more. But I think what's interesting is for me, you get the balance down the straw first, and then you match the singing without the straw to the balance.
Yes, I think that's really important.
Gillyanne Kayes 12:05
So you think you are forming the vowels internally, if you're bringing the vowels in And by and large vowels are made with different shapes of the tongue, so that's, that's fine. There's maybe a little bit ofer- or oo-ishness because of the lip position. But yeah, I think that's a very good interim step.
By the way, I was practising yesterday, and I was practising I didn't realise that's what I was practising, but I ended up doing improving my harmonics singing, my overtone singing, which has I actually started to get really clear overtones by singing by doing a different vowel shapes down the straw.
Interesting. That's cool. What what kind of straw were you using?
I on at that point, I think I was on a seven inch, I thought a seven, seven inch, hello? Seven millimetre. I have a very large mouth...
Gillyanne Kayes 12:53
This is the seven millimetre straw.
I normally stick with the 10 millimetre because I like it the most. But actually, the 10 didn't work as well. So I think I was on a seven.
Gillyanne Kayes 13:05
I'm loving the seven at the moment thing.
Gillyanne Kayes 13:08
So, um, just a quick interim question for me, really, I was thinking about the, you know, the acoustic effects, effects of working with a straw. We don't get that benefit when we're working with a straw in water, though, do we because although water does transmit sound, we're not getting that lovely tooing and froing of the acoustic sound wave within the the tube. I'm right on that aren't I?
Yeah, the thing about the water is it kind of acts as like a little bit of like a muffler. It the second you direct that acoustic energy down into the water, you kind of just dilute it and dissipate it. And so you don't, you don't get a lot of the resonant boosts as a result of just using the tube external from the water. But also with that, just over the last couple of days, I was really thinking about material properties. Typically, the kind of things you do with water are with potential like a silicon tube that's maybe a bit wider. And the silicon itself isn't going to allow for those sounds, and acoustic energy to bounce around within, it's going to kind of absorb it. Whereas something like a stainless steel or a plastic that's a bit more reflective will allow for those boosts. So material properties, I think, play quite a big difference when you're talking about acoustics.
Gillyanne Kayes 14:31
I'm glad you've raised that. And just for those who are watching on YouTube, I waved to Dr Vox at everybody at that point, which is a silicon tube. And of course this one is an Oren's lovely, high grade steel. Is that right?
Gillyanne Kayes 14:45
I'm wondering if we could go to Pippa's question because she had a very interesting question.
Yeah. So Pippa says when I'm singing through the OB1 straw which is the straw that Gillyanne's holding at the moment, I sometimes hear a stream of air as well as my voice through the straw. I don't normally hear this error using straws made of other material, I can eliminate this air noise if I don't blow as hard. Could it be the material? Or am I just blowing too hard?
Okay, yes, there's a few things happening here. The... talking about the physics very quickly of what's happening with our straw compared to others, a normal straw, you just have a unrestricted fixed length that air can flow through. With ours, we have a range of contracted sections and expansions. And we know that as air moves to an area that is smaller, so if it moves from a high area to a low area, the speed of that air is going to increase. And so you kind of have slow then fast and slow than fast and slow and fast. And those rapid changes, I mean, in essence, create almost like a whistle-like effect. So that's one of the the components, it might be that it's just a phenomena of the way the air is just moving through the tube. On top of that, then, if you are slightly, if you have slightly high pressure to begin with, the overall air speed is going to be increasing. When it comes to those contracted sections, the air is gonna be moving faster, which creates more of that whistle. I mean, it's basically the same way as you whistling with the lips.
It's interesting because I started experimenting,
Gillyanne Kayes 16:31
I did the same
thing said that and I'm actually gonna do a little experiment.
Gillyanne Kayes 16:35
You share yours, I'll share mine.
Okay. I want to do it with with your straw and a standard plastic one, which I think is a seven
Gillyanne Kayes 16:45
That looks like a seven
Okay, so I'll do it with the no I'll do it with yours first. Hang on, I have to take the end off
Gillyanne Kayes 16:53
Yes, super narrow if you're a bass.
So, um, what was interesting is that I started with the air sound and then brought voice in to see what I could do.
So this is interesting. The air sound carries on the whole time.
And I wondered whether I was actually doing a slightly breathy sound so that the closure at vocal folds level was a little loose. So I thought what would happen if I closed a little stronger?
And the answer is the sound goes down. So the breathy sound diminishes. Could I then get an completely unbreathy sound? I mean, basically, can we lose the sound of the breath turbulence at all, and I thought ooh, gotta try this.
Now, what I started to play around with was my tongue position. And I discovered that if I've got a deeper tongue position, I get more air turbulence. And if I've got a high fronted tongue, I get less air turbulence. I don't know what that means, but it works every time.
Gillyanne Kayes 18:17
Okay, I'm going to pitch in. I know that Pippa's a classical singer. So I did a bit of, you know, sort of lyrical singing down the wide straw. Well, the sort of round this end here. I can hear air. Now if I do
which is my non lyrical voice. I don't hear any air.
That's your M1
Gillyanne Kayes 18:49
The other thing I found was that when I used this is a biodegradable straw. This is my lyrical.
I didn't get so much hiss, I thought. For me, I think it's to do with the position of the lips that this is a bit heavier.
Gillyanne Kayes 19:12
And what I found was, I wasn't actually puckering in the same way. So that might be a factor to look at, huh?
Yeah. Yeah. Yes. That's so interesting. I think that there's a couple of other things also going on here that potentially compound all of that the... With ours, because of the way the sections are connected together. Essentially, we have a connected piece here and a connected piece here. If, depending on on the flow, there is a chance that air can leak through these sections, which might create that sound. I think it's minimal. If you like super high pressure, then you're probably going to get a little bit more leakage. But I think the other probably more interesting thing that might be happening is I wonder if we are... I wonder if the material itself is boosting the sound of the air stream. In addition to the other harmonics at play,
Gillyanne Kayes 20:21
This is what I was wondering if you were getting a kind of an acoustic artefact from from the material. And that you shouldn't really worry about it, I don't think but I was so interested when I saw Pippa's question. Yes, I know, her singing. And I thought, well, this is not a singer who sings with a lot of air. She's got great control. And I found when I sang in my classical voice, I had exactly the same effect with the metal straw. Hmm. So something to notice, it's just a geeky thing.
We've been talking about the OB1 straw. For those of you who aren't watching on on YouTube and are listening to the podcast, I just want to describe it, I want you to imagine a little telescope. Because the telescope expands and contracts, you pull it out to see further and you push it in not to see as far or when it's when it's at rest. And this one has got three sections, which are get slightly bigger as they go down to the end. Well, I say the end, but you can play down both ends of it
Can you hold it up for the Youtubers?
Not at the same time. But this is for YouTube, this is the OB1 straw. And in fact, this one has a little piece that goes on the end, which also gives you more possibilities. But the interesting thing about OB1 straw is because it is wider at one end than it is at the other. If you blow down from the narrower to the wider end, you get less back pressure.
Gillyanne Kayes 21:46
We've got that right haven't we?
Yeah. And if you blow from the wider end down to the narrower and you get more back pressure
Gillyanne Kayes 21:52
Well the back pressure will increase as it goes along
It's specifically because the tube gets narrower.
And in fact, obviously, because it's expandable, you can pull it out to its full length, which will also increase the resistance. And you can reduce it to in fact its shortest length, which will make the resistance slightly lower. So in fact, you have a lot of different variations.
Gillyanne Kayes 22:16
Are we going to attempt to define back pressure?
Gillyanne Kayes 22:20
Shall we go there?
Let's talk about backpressure
In fact, hang on. Somebody sent a question.
Gillyanne Kayes 22:25
We've got some great questions about that
We did it was...
Gillyanne Kayes 22:29
Was it Lorraine?
No, it was Monia. Yeah, right Monia again. She said, "Oh, and another one? I have trouble of formulating this question. So I hope you get what I mean, maybe I'm completely on the wrong path here. I'm sort of struggling with this whole sub glottal pressure, airflow, back pressure thing. Some students find it really hard to feel the difference between airflow and air pressure / subglottal pressure, they just record a sensation in their abdominal muscles and can't really tune into the feeling of the larynx. What do you think would be good SOVT exercises to differentiate between them? Is it just using different straw widths and lengths? Because obviously, breathing through a wider straw means less back pressure? So I'm sure it would also have an effect on the airflow and the sub glottal pressure?" Really great question.
Okay, there's a lot there
There is a lot to unpack.
Gillyanne Kayes 23:20
Yeah, she's a very experienced teacher and singer.
I don't have the question in front of me. Can you give me the bullet point rundown again, because there's a lot to unpack.
What's the difference between airflow, air pressure, sub glottal pressure? And how would the students feel it?
Okay. So, when we're talking about... let's just quickly clarify flow for a second. So flow flow is basically just the movement of air. And it can be at varying speeds. Yes. Typically. And I say typically, the pressure and flow are, they kind of track each other. If you increase the pressure, it is likely that you will also increase the flow I'm saying likely because it's not an exclusive you can have a lower pressure but a greater flow. So we're kind of going you know on the typical here, so then you know, the pressure is the How do I easily explain pressure?
I can I can come in at some point because I've got some ideas.
Gillyanne Kayes 24:38
I have some exercises that people can feel it
Okay, I am gonna come in here because
I want to separate things out. Okay. Yeah, far as I'm concerned, flow is mainly controlled by the lungs.
Which is the amount and speed of air that comes up to vocal folds. Pressure is a combination of that flow, and how much the vocal folds resist it.
Gillyanne Kayes 25:08
And when people talk about sub glottal pressure, it's actually the measure of the pressure
just underneath the vocal folds
Gillyanne Kayes 25:14
Just below the vocal folds, which can only be measured directly by having a tube put in through the trachea, which has been done in research
Gillyanne Kayes 25:27
But it can also be measured at the lips with typically in the Swedish research, they use the sound pa, pa, so they measure the changes between the the unvoiced amount of air used to further the unvoiced p and then moving into voice. And all of that is noted in a massive collection of research.
Can we break this down even more?
I don't think in the explanation you just gave about pressure, I don't think it's exclusive to flow. You can you can have you can increase the pressure without having any movement of air. Which is interesting, because then
Really? How do you do that?
So I'm thinking about I'm thinking about Pascal, here.
In that if you have a change in pressure, one point of the system, it is equal all points of the system without necessarily there being a need for any flow of air. So you can essentially you can close off.
Oh, yeah ok
a system. Yes, pressurise it. But no air is moving. You're just reducing the volumatic space, but you're not allowing the air to flow outward.
You're definitely not allowing the air to flow outwards. That's really interesting. Because you said reduced the volumatic space. And my my translation before you said that was Yes, you're closing, let's say the vocal folds or the lips, whichever, you know, whichever, whichever. And then you're building pressure up underneath. But in order to build up pressure underneath, you have to actually make the air move. Now what you're saying is that the air doesn't move, but you're reducing the volume attic space to increase the pressure of air inside, for instance, the lungs or the throat. Oh, yeah, we're, we're up to full size again, only
Unknown Speaker 27:29
Oh, you can do it, you can do it.
So this is the interesting thing. Because if you just close your lips, and you don't do that the air doesn't move and nothing happens. You've literally you've just got nothing, you've got a closed loop a closed canister if you like
Gillyanne Kayes 27:43
Can I just show you something? This is not recommended, listeners. Take a breath in and close your glottis.
Yes. Hold your breath, yep
Gillyanne Kayes 27:51
Yeah. So now we have the same lung volume and the glottis is close. Yeah. And now push up with the abdominal contents. So you're pushing your diaphragm. So you're making the chamber smaller and thereby increasing the pressure underneath the glottis.
then, yeah, so are we then saying flow is the movement of a volume of air from one place to another? Whereas with this here, we're talking about essentially now a closed system, where the volume of air is the same. But we are essentially compressing it to pressurise air. Air is incompressible. So there's an issue there, but the idea is the same. We're compressing the chamber.
Okay, yeah, we are actually talking about exactly the same thing. It's just I'm looking at the air and what it does, and you guys looking at the canister and what it does
but it is exactly the same thing.
Gillyanne Kayes 28:48
Well, what was Oren's idea that when we've closed the system? Now obviously when we're vocalising, the system is always open in something which is where I think Ohm's law comes into play.
The reason that I'm... as a singer, the reason that I'm I'm interested in this is because you can set your vocal folds vibrating, and then you can make your air travel faster. And that's flow. And in a way that's not to do with resistance. It's not to do with subglottal pressure, subglottal pressure is a result of it, rather than an action. And actually, if you don't, if you keep the sub glottal pressure the same and you increase the the flow speed, you start to blow your vocal folds apart, and you are more likely to get a breathy sound.
Yes, but then you'll also decrease the pressure at the lung level as a result.
Quite more rapidly
More rapidly. Yes
We are talking the same thing. Yes. Yeah. It's a terminology thing
Gillyanne Kayes 29:50
That's good you're coming in from different sides. Can I move into practical because we're all having a lovely time. First of all, I think one of my responses to you Monia would be well yes, it is hard to feel subglottal pressure. Because we're not really meant to be feeling things at vocal fold level. You know, we're not... our neural system isn't set up to do that, although we can build in proprioceptive feedback. So a typical way I would do it, to not stress the system too much would be to get people to close their lips and puff up their cheeks.
If you close your lips and allow your cheeks to puff up, as Gillyanne is demonstrating beautifully now,
Gillyanne Kayes 30:34
Like a blowfish.
Yeah, what happens?
Gillyanne Kayes 30:36
You feel pressure behind your lips, right? So you feel that sense of back pressure. If you then start to make a little hole in your lips. I'm not going to make a fart noise but we'll see
Welcome To Vocal Process
Gillyanne Kayes 30:50
vocal farts these are... Now I'm obviously not vocalising yet. But I think this is where the you know, the puffy cheeks exercises come from, that you'll read about in Janice Chapman's book where you're doing whoo. And you can do degrees of puffiness. So with if I wanted more flow from my students, I would get them to puff up their cheeks quite a lot. If I wanted less flow for someone who was maybe more of a CCM singer, I would I just say pouty lips. And I find that that balances the pressure and flow better. So Monia, maybe you would try that first because students can feel that. And then you can... what you've done then is you've raised a bit of awareness from them. And then when you start to use the straws, you can ask them to say, Well, does it is that giving you? Do you feel that's giving you more backflow more back pressure or less back pressure? And just use the words that seem to make sense to your student
And I want to go to another bit that she said in the question, which is they just her students just record a sensation in their abdominal muscles and they don't tend to focus on the larynx. And the abdominal muscle thing is a byproduct. If you have well in fact, you can all do it,
Gillyanne Kayes 32:19
it is a much stronger sensation. That's the problem.
Yeah, if you close your lips completely, so you're closing everything and then you try and push air out. What's happening is that you are working against resist... a LOT of resistance as in there is no exit. And your abdominal muscles then kick in to try and work harder to push something out. And they are big muscles so that you're much more likely to feel those than you are the much smaller ones.
Gillyanne Kayes 32:48
Right. Well, that was fun wasn't it.
that was a long answer!
Gillyanne Kayes 32:50
Where are we going next? Thank you for that Monia, because I think a lot of singing teachers will relate to that question.
And this has been so amazing and so intense. We actually think we're gonna have to split this into two. So I'm going to just say thank you to Oren just for this one. There will be another episode out with the rest of what we're talking about coming out soon
Gillyanne Kayes 33:09
to be continued
to be continued.
This is a verse, a podcast with Dr. Gillyanne, Kayes and Jeremy Fisher.