Musicians need to have a good perception of how they are playing in order to maintain control over their instrument when they play in a band. Often each band member will have the tendency to increase the volume of his or her amplifier or play louder during a rehearsal or performance to get clearer acoustic feedback. The result is that the sound level may be so high that it might be wise to wear hearing protection for safety, but it does not help the musician to play better. This is the reason why in-ear monitors have become more popular. Each musician can select his mix of what he wants to hear through individual feedback, and at the same time be protected from louder sound levels.
The problem is slightly different for musicians using hearing aids and playing in a band with amplified music. The hearing aids might not really help to hear loud music and they might produce some distortions of the music due to the maximum power output and the limitation of the input dynamic range. In this case, hearing care professionals might be challenged when they need to recommend a solution or fit a specific live music program. Without the possibility to have an in-ear monitor, it might be wise to replace the hearing aids with hearing protection to avoid distortion and protect the musician’s residual hearing. But this solution might not be ideal for understanding and communicating with the other musicians.
There is another solution for this situation that comes without compromise: turn your clients’ hearing aids into in-ear monitors. Today, it is possible to stream music or an audio signal to hearing aids via a smartphone, the SoundClip-A, or the TV-A adapter. The TV-A can receive the signal of interest directly from a mixing console, like any in-ear monitor, and then send the audio signal directly to the hearing aids.
The hearing aid will still provide correction for frequencies that are not perceived well for speech when the band is not playing, and at the same time provide attenuation of the surroundings with closed acoustics. There is even the possibility during the fitting process, to optimize the balance between the hearing aid microphones and the TV-A input to -12 dB to improve the instrument-to-band ratio. With this fine tuning, the musician will receive clear feedback from his instrument and at the same time protection from the loud sound levels from the band.
We have recorded some short excerpts under different conditions to demonstrate the potential of this solution. A backing track was played from 4 loudspeakers placed around a head and torso simulator. The guitar part was played live twice: the first time without the TV-A and then a second time with the signal from the TV-A. A condenser microphone picked up the guitar part from the amplifier and was also connected to the TV-A via a portable recording station that will take the role of the mixing console.
The first recording, from the reference microphone, gives a good idea about the balance between the guitar and the backing track. The reference microphone was placed in front of the head. The equivalent sound level, measured during the excerpt, was around 87 dB SPL, which is high enough to warrant the use of hearing protection over time.
The second recording is taken from a hearing aid with a flat 10 dB insertion gain. You will notice that the overall loudness fluctuates. This behavior reflects the adjustments from the MPO and the management of loud input levels.
The last recording is made with the TV-A signal with the same hearing aid settings as those used for the second recording. The guitar-to-band ratio is the highest in this last example: you should clearly hear all the attack and playing nuances of the guitar part, and at the same time notice that the band level is much lower than for the other recordings.
Imagine that the musician must play for hours and needs to clearly hear his instrument without increasing the volume of the amplifier. The last example seems to provide a satisfying solution and at the same time the musician can benefit from the hearing aids’ amplification for better communication during the pauses with the band members.
The recordings and this article are based on a suggestion from two colleagues working for Bernafon Germany - Carsten Braun and Dirk Faber. They recommend using the TV-A also to practice at home by directly connecting the output of the instrument to the TV-A. This feedback is precious for us, it helps us to better understand the needs of our customers and discover different ways of using accessories with hearing aids.