Associate Professor of Voice, Shenandoah Conservatory Artistic Director of the CCM Vocal Pedagogy Institute
If you work with opera singers or belters, you have probably encountered a student who does not understand how loud she is when she sings. I was one of those students myself. I would hear my classmates make big glorious sounds and then when I would try to match them, I would be told I was pushing. When I backed off, I was told I was just as loud as everyone else, but to me, it felt like I was singing with half the volume of everyone else around me. I became interested in voice science because it helped me understand things that made no sense, such as the idea that doing less is more. As I researched, I discovered the reason I never understood how loud I was is that I have a strong acoustic reflex, also known as the stapedius reflex.
While I usually avoid citing Wikipedia, in this case, their definition is the most concise:
“The acoustic reflex (also known as the stapedius reflex, middle-ear-muscles (MEM) reflex, attenuation reflex, or auditory reflex) is an involuntary muscle contraction that occurs in the middle ear in response to high-intensity sound stimuli or when the person starts to vocalize.” (1)
The key phrase for our purposes is “when the person starts to vocalize.” The reflex kicks in when sound surpasses the individual’s threshold, which is usually between 70 and 100dB (2). While there is a delay of at least 100ms before the reflex responds to external sounds, when we vocalize, our body responds immediately (3). Studies indicate that the acoustic reflex reduces our perception of our own amplitude by around 20 dB! So, if you are singing at 100 dB, it is likely you will think you are only singing at around 80 dB because of the acoustic reflex.
If you have ever been next to someone who is talking on the phone and seems to be yelling as they talk, they are likely fighting against their acoustic reflex. The phone is directing sound into their eardrum at a high amplitude level and as they attempt to match that level in return, their acoustic reflex kicks in making their voice seem quieter than it actually is. To compensate, the person begins talking louder and louder to try to match the volume of the voice coming through the phone. However, because of the acoustic reflex, it is a loosing battle and the results can be rather annoying for everyone else in the room.
One key bit of information from above is the threshold at which the reflex kicks in. You may be reading this and thinking “well I have the opposite problem with a lot of my students, they don’t sing loud enough.” If their threshold is 70-80db and they never surpass that amount, meaning they sing quieter than they speak, the reflex will never kick in. So in those instances, the student does need to embrace their “loud voice.” However, if the singer in front of you is constantly “screlting” (4), it is likely because they have a strong acoustic reflex and cannot accurately assess the volume of their own voice.
When I encounter a student who has this issue, I tell them about the acoustic reflex and then use a decibel meter to demonstrate it to them. We have lab grade SPL meters in our voice lab at Shenandoah Conservatory, but I find that an iPhone app is sufficient to teach this principle. My app of choice is “Decibel 10.” I place my iPhone on a music stand about two to three foot in front of the singer and then stand right next to her. I ask her to sing a pitch at full volume; we watch the meter and take note of the average SPL. I then have her listen while I sing a note at the same volume level (according to the reading on the meter). After I sing, I ask “so was I as loud as you?” About ninety percent of the time the answer is “no you were louder,” which is followed by a laugh as they realize their ears are deceiving them. We do this several times back and forth so that they can process what they are experiencing. I then have them sing a note in the middle part of their range at 100% volume and then have them start reducing their effort by 10% with each repetition until they find a vocal production that requires less effort but produces the same amplitude according to the decibel meter. They are almost always amazed that they can sing at 80% of their usual effort level and achieve nearly identical results according to the SPL meter. When we play back a recording of them singing, they also usually notice that when they sing with less effort, the sound is more marketable. I have them download the app and use it as a practice tool the following week. In most cases, the pushing stops within a week of using the app.
I have found this exercise to be incredibly helpful for singers of all genres. As mentioned above, the threshold can vary between 70-100 dB, meaning some singers are going to have a stronger reflex than others. However, for those who have a strong reflex, this information can have a huge impact on their vocal progress. Do you teach your students about the acoustic reflex? If so, please tell us how in the comment section below. If you are not already following the blog, you can sign-up below to receive an email each time there is a new post. If you enjoyed this article please share it on social media. As always, thank you for reading and have a great week of teaching! ~ Matt