Rhythm R3710预配置DSP系统实践应用指南

into account. Finally, the noise reduction gain is also adjusted to take advantage of the natural masking of ‘noisy’ bands by speech bands over time.

Based on this approach, only enough attenuation is applied to bring the energy in each ‘noisy’ band to just below the masking threshold. This prevents excessive amounts of attenuation from being applied and thereby reduces unwanted artifacts and audio distortion. The Noise Reduction algorithm efficiently removes a wide variety of types of noise, while retaining natural speech quality and level. The level of noise reduction (aggressiveness) is configurable to 3, 6, 9 and 12 dB of reduction.

In−Situ Datalogging − iLog 6.0

Rhythm R3710 has a datalogging function that records information every 4 seconds to 60 minutes (programmable) about the state of the hearing aid and its environment to non.volatile memory. The function can be enabled with the ARK software and information collection will begin the next time the hybrid is powered up. This information is recorded over time and can be downloaded for analysis. The following parameters are sampled:

Battery level Volume control setting Program memory selection Environment Ambient sound level Length of time the hearing aid was powered on The information is recorded using two methods in parallel: Short−term method − a circular buffer is serially filled with entries that record the state of the first five of the above variables at the configured time interval. Long−term method − increments a counter based on the memory state at the same time interval as that of the short−term method. Based on the value stored in the counter, the length of time the hearing aid was powered on can be calculated.

There are 750 log entries plus 4 memory select counters which are all protected using a checksum verification. A new log entry is made whenever there is a change in memory state, volume control, or battery level state. A new log entry can also be optionally made when the environmental sound level changes more than the programmed threshold, thus it is possible to log only significantly large changes in the environmental level, or not log them at all.

The ARK software iLog graph displays the iLog data graphically in a way that can be interpreted to counsel the user and fine tune the fitting. This iLog graph can be easily incorporated into other applications or the underlying data can be accessed to be used in a custom display of the Information.

Tinnitus Treatment

Rhythm R3710 has an internal white noise generator that can be used for Tinnitus Treatment. The noise can be attenuated to a level that will either mask or draw attention away from the user’s tinnitus. The noise can also be shaped using low−pass and/or high−pass filters with adjustable slopes and corner frequencies. The noise can also be duty cycled. The on and off time of the noise stimulus can be adjusted so that the on time is from 1 − 30s as well as the off time. An off time set to 0s turns off the duty cycling.

As shown in Figure 1, the Tinnitus Treatment noise can be injected into the signal path either before or after the volume control (VC) or it can be disabled. If the noise is injected before the VC then the level of the noise will change along with the rest of the audio through the device when the VC is adjusted. If the noise is injected after the VC then it is not affected by VC changes.

The Tinnitus Treatment noise can be used on its own without the main audio path in