"Effects of HearFones on speaking and singing voice quality" (Abstract)
Department of Speech Communication and Voice Research, University of Tampere, Tampere, Finland
Laukkanen AM, Mickelson NP, Laitala M, Syrj? T, Salo A, Sihvo M.
HearFones (HF) have been designed to enhance auditory feedback during phonation. This study investigated the effects of HF (1) on sound perceivable by the subject, (2) on voice quality in reading and singing, and (3) on voice production in speech and singing at the same pitch and sound level.
Test 1: Text reading was recorded with two identical microphones in the ears of a subject. One ear was covered with HF, and the other was free. Four subjects attended this test.
Tests 2 and 3: A reading sample was recorded from 13 subjects and a song from 12 subjects without and with HF on. Test 4: Six females repeated [pa:p:a] in speaking and singing modes without and with HF on same pitch and sound level. Long-term average spectra were made (Tests 1-3), and formant frequencies, fundamental frequency, and sound level were measured (Tests 2 and 3). Subglottic pressure was estimated from oral pressure in [p], and simultaneously electroglottography (EGG) was registered during voicing on [a:] (Test 4).
Voice quality in speech and singing was evaluated by three professional voice trainers (Tests 2-4). HF seemed to enhance sound perceivable at the whole range studied (0-8 kHz), with the greatest enhancement (up to ca 25 dB) being at 1-3 kHz and at 4-7 kHz. The subjects tended to decrease loudness with HF (when sound level was not being monitored). In more than half of the cases, voice quality was evaluated "less strained" and "better controlled" with HF. When pitch and loudness were constant, no clear differences were heard but closed quotient of the EGG signal was higher and the signal more skewed, suggesting a better glottal closure and/or diminished activity of the thyroarytenoid muscle.
We got an excited phone message: "I am lead of 1992 champion Sweet Adelines quartet, saw and heard HearFones being used by a quartet I was coaching and found them to be one of the most exciting and effective things for singers I've ever seen or heard. I coach a lot of quartets and choruses and could sell a ton of these things. I would like to become a dealer."
A choir director from Austin Texas called that she received her HearFones. "They're great; work just fine. Can I get a better price by the dozen? I'm bringing it up before the music committee." (Yes, she can get a better price by the dozen).
Choir director Sally Trice says, "I find HearFones helpful with singers' intonation, and the rest of the choir notices the difference." She continues, "They often make the singers' voices seem softer and (they) sing with better fidelity and less distortion. The choir then blends better. One of my singers especially likes to use HearFones in her vocal warm-ups."
Nancy Lacasse writes, "I want to thank you for bringing me this wonderful invention. For years I've been complaining about not hearing myself or my real voice . . . Now I can correct myself while my jaw and muscles are still in position. It's just wonderful . . . I love these HearFones."
"I work with a jazz trio in which I'm the bassist, vocalist, electronic musician. I love your product. I use it to warm up . . . and next time I record a demo for the band, I will have my HearFones on! I recorded a cassette tape of children's music with my wife and family, and I did most of the vocals. I wish I was using HearFones then. Keep up the good work.
Bill Parsons in Newfoundland says, "The HearFones are fabulous. They enable me to focus more on the quality and accuracy of my singing, as well as blocking out some other folks who do not sing quite on target."
"I am a member of Sweet Adelines International and in a new quartette. I sing bass and have found the HearFones to be invaluable in not only learning my part, but working on vocal production. AMAZING. I think, no, I know the marketability of this product is fantastic."
"I wanted to express how helpful HearFones have been to my singing. The quality of my voice has improved tremendously. I especially like to use them in my vocal warm-up exercises. I simply love this product. Keep up the good work."
"I'm using my HearFones as a singer to help with harmonization. The results have been just great. You can really hear yourself (as well as everyone else)"
"As a 20-year Sweet Adeline veteran, I still couldn't understand what our chorus coaches were trying to tell to us -- until I tried HearFones. I was finally able to hear how those subtle changes in mouth shape, tongue placement, vowel forming, etc., were manifesting themselves in my vocal production. Now I can be my own coach. They're great. I love them. Dr. Ruth Freeman, in Tennessee.
E-mail from David Rourke: "I can hear every glitch. A friend says, 'Helps intonation on every note'. HearFones help solve part problems."
E-mail response: "As a singer of many different styles, I've never found a product quite like HearFones! This unique device allows you to hear very minute fluctuations in volume and tone, thereby illustrating to the user the best possible vocal control with the least possible time and effort. HearFones has my gratitude."
Letter: "Ray, just a note to let you know how much a difference HearFones has made in helping me develop voice control and delivery. I have received many more compliments on singing since I began practicing with my HearFones on. Pat Eisenhart
Letter: "Thanks . . . THEY WORK." LaDonna Thomas, Sweet Adelines Quartette champ
Letter: "I'm using my HearFones as a singer, teacher and chorus director to help discipline the children, who habitually call out without raising their hand, to help them hear what they sound like. The results have been fantastic." Jolie Shushansky, 2nd grade teacher, RI
E-mail: "Little by little, the HearFones began to make a difference . . . everyone began to get on tune. This is the first year we have seen such a dramatic difference in the elementary children's choir. We had three boys in the 7-12 grades that couldn't carry a tune in a bucket, but they now are hearing themselves." Bill and Kathy Gwyer, Robert Shaylor Academy, missionary kid school, (in the jungle) Tamatama, Venezuela
Letter: "At Harmony college I sampled . . . HearFones. They were great. I'd like a pair for my quartet."
Letter: "After 50 years of being afraid to sing, I started vocal lessons determined to set free the singer I'd always believed was in me somewhere. After a year of practicing almost an hour a day, I gave up . . . I felt more and more lost and frustrated and it seemed the more I worked on a song, the worse it got. Two years later . . . I started again. At my first lesson, she loaned me a pair of HearFones and a whole new world opened up for me. I could actually hear what I was singing (or trying to sing!) and I could hear precisely. Turns out my earlier frustration was largely due to not being able to hear clearly what I was singing and if I couldn't hear it, I couldn't sing it. I've been practicing with borrowed HearFones and I am so excited about what I hear! . . . Each time I repeat an exercise . . . I get significantly better because I can hear what I'm singing . . . Perhaps people like me who've always believed they couldn't sing, have never been willing to listen to themselves. HearFones gives us the boost we need to hear and then sing." Pat Murphy
[The following is a message on Ray's answering machine after he had been teaching in a Barbershop Harmony music education school in Ohio and had later sent a set of HearFones to Don Gray, one of the other instructors at the school. Don, a singer, arranger and coach wanted to use the HearFones in his own quartet and show them to others, including Jean Barford, an experienced coach in the Sweet Adelines]
"Hello Ray, my name is LaDonna Thomas and I'm calling about your HearFones. I'm in a championship quartet and was working with Jean Barford yesterday and I got to use your little apparatus and find it the most intriguing thing I've ever worked with. I'd like to know if they're available to be purchased. I have a sale going on for you right now. If you would like to call me, my number is . . . Thank you. Look forward to hearing from you"
[Ray called her to tell her they were not yet in manufacture. However, he offered to send her a prototype set for her use and for our own market testing. Later, she completed and returned two test forms, quoted below.]
"The HearFones force me to pay total attention to what I am doing or not doing. It makes me realize that when I do sing correctly it is total accomplishment and achievement. It is good to hear that concept."
"I sing everything without the 'fones and then put them on and sing the same thing. I allow myself to be critical, and then I allow my brain to fix what is wrong without thought."
"I found that if I sing with more open and resonant sound I don't have to work so hard to do it wrong! This forces me to do things right. When I take the 'fones off I almost feel as if I can't hear. That takes some adjusting."
Q: What ways do you use HearFones with your singers?
A: "While they were working on vocals or singing with someone else."
Q: How do you evaluate HearFones as a tool in improving the vocal quality of your singers?
A: "This is the most natural way of helping the singers fix themselves . . . EXCELLENT TOOL."
Q. How do you improve the voice part balance in your ensemble?
A: "In barbershop singing, one voice can really influence the other three. This tool really makes the whole thing happen!"
Q: How do HearFones impart greater vocal awareness to your singers?
A: "Singers get to hear their own voice for the first time -- it truly helps them to fix what you are asking them to fix."
Q: How do HearFones help improve the tonality of your singers?)
A: "When the singers understand what to listen for without outside noise, it is amazing how they can improve tonality by themselves."
Q: How do HearFones improve the personal confidence of your singers?
A: "After the singers realize that they can do what is asked, they feel a sense of accomplishment, and that is confidence."
Q: How do HearFones help your singers enjoy singing more?
A: "I have a couple of students that want their own HearFones! They enjoy singing correctly and want to get used to the sound."
Q: What techniques did you employ to achieve the same sound quality in (non-HearFones) performance that you heard with singers using HearFones?
A: "I have them sing with them on, then sing with one side up and the other down, then sing one phrase with them on and the next without, etc."
Q: How easily do your singers transfer the knowledge of their true sound (using HearFones) to their subsequent performance without?
A: "Most were able to continue at about a quarter of the time within the first 2 weeks. After a month, they could go 3/4 of the time."
Q: Have your singers used HearFones in public performance?
A: "No, but would like to."
Q: What means did you use to help singers producing too little volume sing up to the level of the ensemble?
A: "The singers needs to trust that they will fix the problem and quit listening."
Letter From Don Gray, 8 July 1997
Dear Ray, I have really enjoyed testing your HearFones! The package arrived just before a 5-hour rehearsal with HIS MASTER'S VOICE (Don's quartet) along with our coach Bob Mucha, and we were intrigued -- and helped! -- with the gadget. In addition, the young quartet, DESPERADO, that I coach, gave them a thorough workout, and they (and I) were equally impressed. They had, the previous week, undergone an extensive coaching session with Jean Barford on sound placement, and so were particularly attuned to the possibilities of HearFones. I plan to take them to Southern Gateway (chorus practice) Thursday nite, and show them to Jean. Let me know how I can be of further testing service. MUSICally, (signed) Don Gray
Quartet coach and barbershop judge, at school in Canada used HearFones while working with quartets there. He was asked, "Do they work?" and replied, "Man, do they ever!"
Elvera Voth is using HearFones to teach singing to the inmates of the Lansing Kansas Correctional Facility as a part of her Arts in Prison program. Preliminary reports indicate most heartening results for some singers who are proud of what they're doing, maybe for the first time in their lives.
E-mail: "As a singer of many different styles, I've never found a product quite like HearFones! This unique device allows you to hear very minute fluctuations in volume and tone, thereby illustrating to the user the best possible vocal control, with the least possible time and effort. HearFones has my gratitude."
E-mail: "Hi Ray, Thank you for getting back to me concerning the HearFones. I think they are fabulous, and I use them at home when I am learning songs for the teaching quartet and for my own quartet. Being able to hear how I sound helps me with dynamics, flatting, sharping and makes me an all round better singer. As section leader I regularly use the ones the chorus bought for members of the section. I find they enable members of the section to hear and fix many of their recurring problems. I highly recommend them. They are excellent tools for any singer who wants to improve their craft."
One of the stories: Kevin Patt was in Fayetteville, Georgia, on business, and at supper time took a break for something to eat. He went to a nearby restaurant that had a piano bar with a man playing and singing. Kevin and his wife Lorraine are both singers, among other things. Fortunately for our story, Kevin had his HearFones handy as he approached the piano man and said, I'd like you to try singing with these HearFones. The singer mentioned that he had just finished his set, but four ladies at the piano cajoled him into singing one more song. When he finished, his audience gave him a great hand (for being such a good sport) and also chattered as to how much better he sounded using the HearFones. (paraphrased from a personal phone conversation)
From a school speech therapist in Maine: "I tried the HearFones with several students and I wish I'd videoed their faces as they heard themselves. It really improved their ability to discriminate and identify sounds, both in articulation as well as phonemic awareness related to reading and spelling. The only part they didn't like was taking turns . . . I'll let you know of the progress. Thank you again."
E-mail: [note: Tammy lives in California, but hails from Maine --- where HearFones are made] "Hello, my name is Tammy Thibault and I was wondering if I could order some HearFones from you. I was just home visiting my family in Maine and my mom had a pair. What a good idea!"
[later letter]: "I'm so excited to be receiving this new thing, from Maine, no less. Now I can tell all my friends more good things about where I come from. Thank you, Tammy"
[even later letter from Tammy] "I love the HearFones idea. I'm getting them for one of my Japanese friends who is in a band with my husband. I hope she likes them. I just seemed like such a cool thing."
"I think they are very cool, and my chorus director has a set"
"Recently I had the opportunity to experiment with a pair of HearFones and was impressed . . . send me some information"
"I am a member of the Idylwild Master Chorale. Mr. X introduced your invention, the HearFones, at our rehearsal. Everyone passed it around and had their own ideas on it, but I think it's the best thing that came along since sliced bread."
E-mail following phone conversation: "Mr. Miller, I am impressed that you are at work on a Sunday! I heard about HearFones in a small Music Catalog that I get: THE MUSIC STAND . . . I have used them with several voice students, with great results . . . It enables the kids to hear themselves . . . which enables them to change the way they sound. I am involved with teaching voice to both young people and adults. I also teach piano and come from a background of 25 years teaching music and directing choirs in the public schools in Minnesota. Yours truly, _____ "
Note from one who had just seen the Singing Better Newsletter: "I think your newsletter is just one wonderful thing for singers. I wish I had seen it years ago when I did more singing. And I like what the 'Fones do to help me, too. Good luck with this. It should help a lot of people all over."
Paul L. Selbst, Ph.D., professional educator, amateur (but enthusiastic) singer
"When the inventors of HearFones approached me to discuss the marketing of their product, I was immediately impressed with its abilities, its simplicity, and its profound effect on the human voice. I am confident that this product will continue to make singing and speech professionals very happy in the years to come" Pat Friedman, President, Friedman Marketing.
E-mail from Ontario: "Hi Ray, You sent my order UPS to Guelph and it arrived on Monday, so that was very quick. Surprised me for sure, because it's usually 2 or 3 weeks. Tried them out at rehearsal last night and I thought they were awesome. Put up with quite a bit of kidding about what time my plane was landing, etc., but mostly there was a lot of curiosity and 'Can I try them?' Each and every one said 'Wow'." a Sweet Adelines singer
"Dear Mr. Miller, Per our conversation this last week, I am writing you a letter to express my feelings of HearFones. I am a vocal teacher and I, as well as my students, feel they are a very useful tool. At first, I would have to occasionally remind my students to use them. Now they put them on by themselves, knowing that the HearFones will help them hear better, resulting in a better sound . . . I feel the HearFones are great to help singers . . . Thank you for your product"
Soloist and singer: "I practice singing in the car - they're great for that. I can hear the full sound without pushing it."
E-mail from Canada: "Dear Peter and Ray, I am sitting at my computer with the set of HearFones ordered on Feb. 5. It is now Mar. 27. I delivered the second pair to my friend who teaches voice lessons. Already I like the sound of my voice in these things. I may never take them off. The fact that they block or reduce outside noise is a benefit, too, as I have 6 home-schooled children around me 24/7. My children may not appreciate the fact that I can focus on my singing more. Oh, well, all's well that ends well. I received your mailing last Wednesday, and gave my sister the extra set you sent me, and did without till now. What a sacrifice that was.
"God bless you for your kindness and business ethics. (a happy customer at last)"
"Dear Pete and Ray, I am interested in purchasing a set of HearFones. I've tried them and they're great! Please e-mail me with purchase and order information. Thank you, ______ "
"Hey Gang! My name is ______ from New Jersey, and I got a pair of HearFones for my birthday. I've been singing karaoke for about seven years. Although I'm said to be pretty good, I knew there was room for improvement so when I saw your ad and the claims that were made I was more than a bit curious. But what I didn't know was that my girlfriend had also seen the ad and purchased them for my birthday. I have been getting more compliments on my singing, because now I have the confidence and ability to go out and sing those songs I used to avoid because I thought I couldn't do them. It was great to know I was totally wrong! It's such a great confidence builder once you start to use them. Thanks for the great music tool."
E-mail: "Said shipment arrived TODAY -- TUESDAY-- What service!!!! (sic) They will be in the hands of members this evening, since this is chorus rehearsal night. What timing!! Thank YOU. Again, thank you for your promptness."
Letter: "Dear NEXTEP, Last week at the SPEBSQSA, Inc. Harmony College, I sampled a pair of HearFones. They were great; I would very much like a pair for my quartet. Would you please send me a price list catalog? Thanks."
From user comment card: "I'm using HearFones as a singer to help with my own voice and to help train my daughter. The results have been great. It really helped. I was surprised at the tone. It really helped my daughter also . . . Am going to take it to our coach. I think she'll really like it. Thanks, ______ "
E-mail: "Ray, Just a note to let you know how much difference HearFones has made in helping me develop voice control and delivery. I have received many more compliments on singing since I began practicing with my HearFones on. Many thanks, Pat Eisenhart"
From an attender at one of our HearFones workshop: "Interesting --- Learned about various sounds"
From user comment card: "HearFones help me with my studies at a music school. The result has been much improved quality in my voice. From her later letter: I wanted to express how helpful HearFones have been to my singing. The quality of my voice has improved tremendously. I especially like to use them in my vocal warm-up exercises. I simply love the product. Keep up the good work. Sincerely, ______ "
From user comment card: "HearFones help the quality of my sound. Come up with more devices for singing."
From user comment card: "I'm using HearFones as a solo performing singer to help with hearing what the audience hears."
From user comment card: "I'm using my HearFones as a choir member and student to help with many different areas of vocal music. The results have been surprising."
Excited and amazed responses like "WOW" and "Cool" and "I've never heard that before" are frequent when people first sing with HearFones.
Letter: "Dear Ray,
"If you took my Physics of Sound class at Harmony College when it was at Albright College, that was a long time ago. I am pleased that your interest in that perspective on our hobby led you to develop the HearFones. They work extremely well. I note that the shape of the clear plastic pieces that funnel the sound are almost exact replicas of the contour of the ceiling of the Mormon Tabernacle in Salt Lake City where a pin dropped on the floor near the focal point where the choir sits can clearly be heard at the corresponding focal point at the rear of the auditorium. But, after all that is precisely the point of your device You received good counsel from Professor Walkling. (Physics Dep't, University of Southern Maine)
"The box containing the HearFones you sent to me arrived on a Friday afternoon just as I was about to leave to be a quartet coach at an LOL Mini-HEP school in LaCrosse, WI. I took them along with me and showed them off to several people, all of whom found that they really changed their perspective. They proved to be particularly effective on quartet members (non-leads) who, without realizing it, were dominating the sound. The HearFones quieted them down instantly. The Bari in my quartet is constantly being reminded by the Lead that the Bari part is not the melody. The Bari claims that he has to sing that loud in order for him to hear himself well enough to tune his notes. The HearFones worked well on him as well. The remaining question is, how do you get his behavior to change when not wearing the HearFones ?
"The teaching quartet at the school was The Ritz (past International Barbershop Champions). All members either are or were music educators. Nick Nickol remarked that he has used a similar device made of selected pieces of PVC pipe fittings with his students to accomplish the same type of aural feedback to the singer. I don't know what you are pricing these units for, but having priced the appropriate PVC fittings, I think you can still be competitive while at the same time freeing up the hands to hold music, etc.
"If you would care to discuss this further, I will be in Atlanta this coming week for the (barbershop) convention and International Contest and staying at the Hyatt Regency headquarters hotel.
"Thanks for sending me a pair of HearFones. I suspect that their use will be integrated into my course on the Physics of Sound. Sing-Cerely, Jim Richards" (Ph D. in Physics, Sound Judge in the Barbershop Harmony Society, past International President of the Society, and quartet singer)
From a second grade music teacher: "HearFones: Enclosed is the writing and drawing of my second grade music classes after their first experience using the HearFones. We began our music lesson responding to spoken, sung, melodic and gestured directions, then sang a review song and a new song using visuals for form and good pronunciation of the text. The writing was done after each child had the opportunity to come to the front and say: "What does this sound like?" while wearing the HearFones In small groups. The students talked freely about their feelings, then shared these thoughts in the large group, with the teacher facilitating the use of music vocabulary.
"We have been enjoying the HearFones and find them extremely helpful in our music program at G.J. West Elementary School. Sincerely, Jolie G. Shushansky, Music Educator"
"Hi, I have just received my HearFones and must say what an aid they are. Have you any outlets in the UK? If not, what would price be for bulk orders and how much. Best regards, ______ "
E-mail letter from Stewart Shuster, Director of the Southern Maine Boys and Girls Chorale:
"A device, such as HearFones, which enables a singer to have the experience of hearing him/herself mostly through the ears and not so much through bone conduction improves intonation. And after several minutes, the throat muscles tend to begin the relaxation process which is so necessary for good voice production -- that kind of voice production which uses relaxed throat muscles and permits the larynx to drop or be used in a relatively low position without fluctuating in level as the pitch of the musical notes being sung goes up or down.
"Bel Canto voice production is that kind of singing in which the muscles of the throat (especially those around the larynx) are relaxed. The larynx should not rise as the singer sings higher pitches, If the muscles surrounding the larynx remain relaxed so that the larynx remains relatively low (but not artificially pulled down) throughout the scale, the singer makes the most efficient use of the voice. The range is increased, the power is increased, the tone is at once more beautiful with both carrying power and qualities that blend with other voices.
"Teachers of singing use a variety of images to get a student to this kind of vocal production, It is important for the student to be aware of what he/she feels as opposed to what he thinks he hears. We have a very inaccurate perception of our own voices until we wear a device like the HearFones which, so far as I know, is unique. HearFones enable a singer to hear his voice directly through his ears rather than through bone conduction and room reflection. The singer, after recovering from the initial shock of hearing himself sound so differently than his previous perception, begins to improve intonation, tone quality, and other niceties of voice production."
User comment card from barbershop singer: "I'm using HearFones for help in improving tone quality - reducing the edge. The results have been very good so far. I am still trying to interest others in the chorus."
From user comment card: "I'm using my HearFones to help with balancing my vocal dynamics. The results have been very promising. Do you have quantity discounts?" (We have; Editor)
More from director Stewart Shuster: "Singers have a very innaccurate perception of their own voices until they wear . . . HearFones. They enable one to hear directly through the ears rather than through bone conduction and room relections."
Letter to Pete: "Greetings, You may or may not remember me, but you gave me a pair of HearFones at Pilgrim Lodge last summer to take back to school with me to Lawrence University.
". . . I didn't use them at first, however as my voice grew in both size and freedom certain issues regarding a vibratoing of the voice began to occur. My past habits had been to hold the tone alla pop style, and in working to get rid of some of that we went a bit too far and there was a little forced vibrato on some vowels in the upper registers. This also created a slight pitch problem. Not bad, but for a while it was hard to sit properly on the pitch and it would just slouch a bit below. It was hard to correct this problem in the practice room as they were small and created weird reverberations, and so HearFones were employed. I was quite satisfied with the results and they certainly helped me correct this problem."
(Editor's note: Ray, of 'Pete and Ray', graduated from Lawrence, class of '52. As well, Jim Richards, our friendly physicist, is also a graduate of Lawrence U.)
From a singer with 'the BrAVE group': "I'm using my HearFones to help with hearing myself. The results have been spectacular."
Letter to Pete from a young classical singer: "Dear Nils Peter Mickelson: I wanted to thank you for the wonderful HearFones. I am having a lot of fun using them and marvel at the way they work. I can see why many singers love them. I'm one of them. . . . Happy New Year"
From Speech/Language Pathologists:
From Linda Hall, speech therapist in Maine: "I tried the HearFones with several students and I wish I'd videoed their faces as they heard themselves. It really improved their ability to discriminate and identify sounds both in articulation as well as phonemic awareness related to reading and spelling. The only part they didn't like was taking turns . . . I'll let you know of the progress. Thank you again."
Pete Mickelson heard about Jenny, a hearing-impaired girl in New Hampshire and sent a pair of HearFones to her teacher for Jenny's use. The following letter arrived: "Dear Mr. Mickelson; Thanks very much for the HearFones. First, I put them on and Jenny signed 'funny'! So, I began singing a nursery rhyme. Then she wanted her turn. As soon as she said 'Mama' she could hear the difference -- to hear the clarity of her voice. She walked about making different sounds and was really listening. This is a wonderful gift we will be working with. Again, our many thanks." (signed) Cindy, speech and hearing therapist in New Hampshire.
"I am a speech therapist in the public schools and just received my new HearFones from Music Stand. They work just wonderfully and should be in speech and hearing catalogs." She mentioned names and numbers for two of them.
We received an excited call from Shannon McIntyre in Florida. She's a speech therapist in the school system and says she just loves our HearFones. She reports that the kids love 'em too and that they are much easier to use than (what) she had been using. She asked if she could get quantity discounts. We assured her that she could.
Excerpts from a letter by Dr. Freeman in Tennessee: "Margit Cummings loaned her HearFones to a girl in our chorus who is partially deaf and can't carry a tune. Well, Margit says she sings in perfect pitch while wearing the 'fones."
I am a speech pathologist at the Voice Research Clinic at the University of Hong Kong. You have kindly sent us HearFones after the PEVOC conference in Stockholm a month ago. We have tried it out with our voice patients. Their responses are very positive. We've got a patient who wants to buy one . . . Thank you for your kind attention. I am looking forward to hearing from you soon."