A woman wearing an in-ear hearing aid listens to a television set at a normal volume of approximately \(60 \mathrm{~dB}\). To hear it, she requires an amplification of \(30 \mathrm{~dB}\), so the hearing aid supplies sound at \(90 \mathrm{~dB}\) to the ear canal, which we assume to be circular with a diameter of \(7.0 \mathrm{~mm}\). What is the output power of the hearing aid?